<?xml version="1.0" encoding="utf-8"?>
<!--Generated by DFIN XBRL Instance Document - http://www.dfinsolutions.com/ - Version R3.0 - on 20-February-2020 [08:26:09] {AM}-->
<schema targetNamespace="http://www.mednax.com/20191231" elementFormDefault="qualified" xmlns:md="http://www.mednax.com/20191231" xmlns="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xl="http://www.xbrl.org/2003/XLink" xmlns:us-gaap="http://fasb.org/us-gaap/2019-01-31" xmlns:country="http://xbrl.sec.gov/country/2017-01-31" xmlns:currency="http://xbrl.sec.gov/currency/2019-01-31" xmlns:dei="http://xbrl.sec.gov/dei/2019-01-31" xmlns:exch="http://xbrl.sec.gov/exch/2019-01-31" xmlns:naics="http://xbrl.sec.gov/naics/2017-01-31" xmlns:sic="http://xbrl.sec.gov/sic/2011-01-31" xmlns:us-types="http://fasb.org/us-types/2019-01-31" xmlns:stpr="http://xbrl.sec.gov/stpr/2018-01-31" xmlns:deprecated="http://www.xbrl.org/2009/arcrole/fact-explanatoryFact" xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:num="http://www.xbrl.org/dtr/type/numeric" xmlns:srt="http://fasb.org/srt/2019-01-31" xmlns:srt-types="http://fasb.org/srt-types/2019-01-31">
<annotation>
<appinfo>
<link:roleType roleURI="http://www.mednax.com/role/CoverPage" id="CoverPage">
<link:definition>1001 - Document - Cover Page</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/CondensedConsolidatedBalanceSheetsUnaudited" id="CondensedConsolidatedBalanceSheetsUnaudited">
<link:definition>1002 - Statement - Condensed Consolidated Balance Sheets (Unaudited)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/CondensedConsolidatedBalanceSheetsUnauditedParenthetical" id="CondensedConsolidatedBalanceSheetsUnauditedParenthetical">
<link:definition>1003 - Statement - Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/ConsolidatedStatementsOfIncome" id="ConsolidatedStatementsOfIncome">
<link:definition>1004 - Statement - Consolidated Statements of Income</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/ConsolidatedStatementsOfEquity" id="ConsolidatedStatementsOfEquity">
<link:definition>1005 - Statement - Consolidated Statements of Equity</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/ConsolidatedStatementsOfCashFlows" id="ConsolidatedStatementsOfCashFlows">
<link:definition>1006 - Statement - Consolidated Statements of Cash Flows</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/General" id="General">
<link:definition>1007 - Disclosure - General</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SummaryOfSignificantAccountingPolicies" id="SummaryOfSignificantAccountingPolicies">
<link:definition>1008 - Disclosure - Summary of Significant Accounting Policies</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/Investments" id="Investments">
<link:definition>1009 - Disclosure - Investments</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccountsReceivableAndNetRevenue" id="AccountsReceivableAndNetRevenue">
<link:definition>1010 - Disclosure - Accounts Receivable and Net Revenue</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/PropertyAndEquipment" id="PropertyAndEquipment">
<link:definition>1011 - Disclosure - Property and Equipment</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/BusinessAcquisitions" id="BusinessAcquisitions">
<link:definition>1012 - Disclosure - Business Acquisitions</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/GoodwillAndIntangibleAssets" id="GoodwillAndIntangibleAssets">
<link:definition>1013 - Disclosure - Goodwill and Intangible Assets</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/DiscontinuedOperations" id="DiscontinuedOperations">
<link:definition>1014 - Disclosure - Discontinued Operations</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccountsPayableAndAccruedExpenses" id="AccountsPayableAndAccruedExpenses">
<link:definition>1015 - Disclosure - Accounts Payable and Accrued Expenses</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/OperatingLeases" id="OperatingLeases">
<link:definition>1016 - Disclosure -  Operating Leases</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccruedProfessionalLiabilities" id="AccruedProfessionalLiabilities">
<link:definition>1017 - Disclosure - Accrued Professional Liabilities</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/LineOfCreditLongTermDebtAndFinanceLeaseObligations" id="LineOfCreditLongTermDebtAndFinanceLeaseObligations">
<link:definition>1018 - Disclosure -  Line of Credit, Long-Term Debt and Finance Lease Obligations</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/IncomeTaxes" id="IncomeTaxes">
<link:definition>1019 - Disclosure - Income Taxes</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/CommonAndCommonEquivalentShares" id="CommonAndCommonEquivalentShares">
<link:definition>1020 - Disclosure - Common and Common Equivalent Shares</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/StockIncentivePlansAndStockPurchasePlans" id="StockIncentivePlansAndStockPurchasePlans">
<link:definition>1021 - Disclosure - Stock Incentive Plans and Stock Purchase Plans</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/CommonStockRepurchasePrograms" id="CommonStockRepurchasePrograms">
<link:definition>1022 - Disclosure - Common Stock Repurchase Programs</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/RetirementPlans" id="RetirementPlans">
<link:definition>1023 - Disclosure - Retirement Plans</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/CommitmentsAndContingencies" id="CommitmentsAndContingencies">
<link:definition>1024 - Disclosure - Commitments and Contingencies</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SelectedQuarterlyFinancialInformation" id="SelectedQuarterlyFinancialInformation">
<link:definition>1025 - Disclosure - Selected Quarterly Financial Information</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SummaryOfSignificantAccountingPoliciesPolicies" id="SummaryOfSignificantAccountingPoliciesPolicies">
<link:definition>1026 - Disclosure - Summary of Significant Accounting Policies (Policies)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SummaryOfSignificantAccountingPoliciesTables" id="SummaryOfSignificantAccountingPoliciesTables">
<link:definition>1027 - Disclosure - Summary of Significant Accounting Policies (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/InvestmentsTables" id="InvestmentsTables">
<link:definition>1028 - Disclosure - Investments (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccountsReceivableAndNetRevenueTables" id="AccountsReceivableAndNetRevenueTables">
<link:definition>1029 - Disclosure - Accounts Receivable and Net Revenue (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/PropertyAndEquipmentTables" id="PropertyAndEquipmentTables">
<link:definition>1030 - Disclosure - Property and Equipment (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/GoodwillAndIntangibleAssetsTables" id="GoodwillAndIntangibleAssetsTables">
<link:definition>1031 - Disclosure - Goodwill and Intangible Assets (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/DiscontinuedOperationsTables" id="DiscontinuedOperationsTables">
<link:definition>1032 - Disclosure - Discontinued Operations (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccountsPayableAndAccruedExpensesTables" id="AccountsPayableAndAccruedExpensesTables">
<link:definition>1033 - Disclosure - Accounts Payable and Accrued Expenses (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/OperatingLeasesTables" id="OperatingLeasesTables">
<link:definition>1034 - Disclosure -  Operating Leases (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccruedProfessionalLiabilitiesTables" id="AccruedProfessionalLiabilitiesTables">
<link:definition>1035 - Disclosure - Accrued Professional Liabilities (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/LineOfCreditLongTermDebtAndFinanceLeaseObligationsTables" id="LineOfCreditLongTermDebtAndFinanceLeaseObligationsTables">
<link:definition>1036 - Disclosure -  Line of Credit, Long-Term Debt and Finance Lease Obligations (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/IncomeTaxesTables" id="IncomeTaxesTables">
<link:definition>1037 - Disclosure - Income Taxes (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/CommonAndCommonEquivalentSharesTables" id="CommonAndCommonEquivalentSharesTables">
<link:definition>1038 - Disclosure - Common and Common Equivalent Shares (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/StockIncentivePlansAndStockPurchasePlansTables" id="StockIncentivePlansAndStockPurchasePlansTables">
<link:definition>1039 - Disclosure - Stock Incentive Plans and Stock Purchase Plans (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SelectedQuarterlyFinancialInformationTables" id="SelectedQuarterlyFinancialInformationTables">
<link:definition>1040 - Disclosure - Selected Quarterly Financial Information (Tables)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail" id="SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail">
<link:definition>1041 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfNetRevenueByServiceLineDetail" id="SummaryOfSignificantAccountingPoliciesScheduleOfNetRevenueByServiceLineDetail">
<link:definition>1042 - Disclosure - Summary of Significant Accounting Policies - Schedule of Net Revenue by Service Line (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfFairValueOnARecurringBasisDetail" id="SummaryOfSignificantAccountingPoliciesScheduleOfFairValueOnARecurringBasisDetail">
<link:definition>1043 - Disclosure - Summary of Significant Accounting Policies - Schedule of fair value on a recurring basis (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfFinancialInstrumentsThatAreNotCarriedAtFairValueDetail" id="SummaryOfSignificantAccountingPoliciesScheduleOfFinancialInstrumentsThatAreNotCarriedAtFairValueDetail">
<link:definition>1044 - Disclosure - Summary of Significant Accounting Policies - Schedule of financial instruments that are not carried at fair value (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/InvestmentsScheduleOfInvestmentsDetail" id="InvestmentsScheduleOfInvestmentsDetail">
<link:definition>1045 - Disclosure - Investments - Schedule of Investments (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccountsReceivableAndNetRevenueScheduleOfAccountsReceivableNetDetail" id="AccountsReceivableAndNetRevenueScheduleOfAccountsReceivableNetDetail">
<link:definition>1046 - Disclosure - Accounts Receivable and Net Revenue - Schedule of Accounts Receivable, Net (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccountsReceivableAndNetRevenueScheduleOfNetRevenueDetail" id="AccountsReceivableAndNetRevenueScheduleOfNetRevenueDetail">
<link:definition>1047 - Disclosure - Accounts Receivable and Net Revenue - Schedule of Net Revenue (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccountsReceivableAndNetRevenueScheduleOfNetPatientServiceRevenueByTypeOfPayorDetail" id="AccountsReceivableAndNetRevenueScheduleOfNetPatientServiceRevenueByTypeOfPayorDetail">
<link:definition>1048 - Disclosure - Accounts Receivable and Net Revenue - Schedule of Net Patient Service Revenue by Type of Payor (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/PropertyPlantAndEquipmentScheduleOfPropertyAndEquipmentDetail" id="PropertyPlantAndEquipmentScheduleOfPropertyAndEquipmentDetail">
<link:definition>1049 - Disclosure - Property Plant and Equipment - Schedule of Property and Equipment (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/PropertyAndEquipmentAdditionalInformationDetail" id="PropertyAndEquipmentAdditionalInformationDetail">
<link:definition>1050 - Disclosure - Property and Equipment - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/BusinessAcquisitionsAdditionalInformationDetail" id="BusinessAcquisitionsAdditionalInformationDetail">
<link:definition>1051 - Disclosure - Business Acquisitions - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/GoodwillAndIntangibleAssetsAdditionalInformationDetail" id="GoodwillAndIntangibleAssetsAdditionalInformationDetail">
<link:definition>1052 - Disclosure - Goodwill and Intangible Assets - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/GoodwillAndIntangibleAssetsSummaryOfIntangibleAssetsNetDetail" id="GoodwillAndIntangibleAssetsSummaryOfIntangibleAssetsNetDetail">
<link:definition>1053 - Disclosure - Goodwill and Intangible Assets - Summary of Intangible Assets, Net (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/GoodwillAndIntangibleAssetsAmortizationExpensesForExistingIntangibleAssetsForTheNextFiveYearsDetail" id="GoodwillAndIntangibleAssetsAmortizationExpensesForExistingIntangibleAssetsForTheNextFiveYearsDetail">
<link:definition>1054 - Disclosure - Goodwill and Intangible Assets - Amortization Expenses for Existing Intangible Assets for the Next Five Years (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/DiscontinuedOperationsAdditionalInformationDetail" id="DiscontinuedOperationsAdditionalInformationDetail">
<link:definition>1055 - Disclosure - Discontinued Operations - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/DiscontinuedOperationsScheduleOfManagementServicesServiceLineDetail" id="DiscontinuedOperationsScheduleOfManagementServicesServiceLineDetail">
<link:definition>1056 - Disclosure - Discontinued Operations - Schedule of Management Services Service Line (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccountsPayableAndAccruedExpensesScheduleOfAccountsPayableAndAccruedExpensesDetail" id="AccountsPayableAndAccruedExpensesScheduleOfAccountsPayableAndAccruedExpensesDetail">
<link:definition>1057 - Disclosure - Accounts Payable and Accrued Expenses - Schedule of Accounts Payable and Accrued Expenses (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/OperatingLeasesScheduleOfOperatingLeaseRelatedRightOfUseAssetsAndRelatedLiabilitiesRecordedOnTheCompanySBalanceSheetAndTheWeightedAverageRemainingLeaseTermAndDiscountRateDetails" id="OperatingLeasesScheduleOfOperatingLeaseRelatedRightOfUseAssetsAndRelatedLiabilitiesRecordedOnTheCompanySBalanceSheetAndTheWeightedAverageRemainingLeaseTermAndDiscountRateDetails">
<link:definition>1058 - Disclosure -  Operating Leases - Schedule of operating lease-related right-of-use assets and related liabilities recorded on the Company's balance sheet and the weighted average remaining lease term and discount rate (Details)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/OperatingLeasesScheduleOfLeaseCostsForOperatingLeasesDetails" id="OperatingLeasesScheduleOfLeaseCostsForOperatingLeasesDetails">
<link:definition>1059 - Disclosure - Operating Leases - Schedule of lease costs for operating leases (Details)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/OperatingLeasesScheduleOfSupplementalCashFlowInformationRelatedToOperatingLeasesDetails" id="OperatingLeasesScheduleOfSupplementalCashFlowInformationRelatedToOperatingLeasesDetails">
<link:definition>1060 - Disclosure -  Operating Leases - Schedule of supplemental cash flow information related to operating leases (Details)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/OperatingLeasesScheduleOfOperatingLeaseLiabilitiesDetails" id="OperatingLeasesScheduleOfOperatingLeaseLiabilitiesDetails">
<link:definition>1061 - Disclosure -  Operating Leases - Schedule of operating lease liabilities (Details)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccruedProfessionalLiabilitiesAdditionalInformationDetail" id="AccruedProfessionalLiabilitiesAdditionalInformationDetail">
<link:definition>1062 - Disclosure - Accrued Professional Liabilities - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/AccruedProfessionalLiabilitiesScheduleOfAccruedProfessionalLiabilityDetail" id="AccruedProfessionalLiabilitiesScheduleOfAccruedProfessionalLiabilityDetail">
<link:definition>1063 - Disclosure - Accrued Professional Liabilities - Schedule of Accrued Professional Liability (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/LineOfCreditLongTermDebtAndFinanceLeaseObligationsAdditionalInformationDetail" id="LineOfCreditLongTermDebtAndFinanceLeaseObligationsAdditionalInformationDetail">
<link:definition>1064 - Disclosure - Line of Credit, Long-Term Debt and Finance Lease Obligations - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/LineOfCreditLongTermDebtAndFinanceLeaseObligationsScheduleOfLongTermDebtDetail" id="LineOfCreditLongTermDebtAndFinanceLeaseObligationsScheduleOfLongTermDebtDetail">
<link:definition>1065 - Disclosure -  Line of Credit, Long-Term Debt and Finance Lease Obligations - Schedule of Long-Term Debt (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/LineOfCreditLongTermDebtAndFinanceLeaseObligationsSummaryOfEstimatedFairValueOfNotesDetail" id="LineOfCreditLongTermDebtAndFinanceLeaseObligationsSummaryOfEstimatedFairValueOfNotesDetail">
<link:definition>1066 - Disclosure -  Line of Credit, Long-Term Debt and Finance Lease Obligations - Summary of Estimated Fair Value of Notes (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/LineOfCreditLongTermDebtAndFinancialLeaseObligationsScheduleOfFinancialLeaseObligationsDetail" id="LineOfCreditLongTermDebtAndFinancialLeaseObligationsScheduleOfFinancialLeaseObligationsDetail">
<link:definition>1067 - Disclosure - Line of Credit, Long-Term Debt and Financial Lease Obligations - Schedule of Financial Lease Obligations (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/IncomeTaxesSummaryOfComponentsOfIncomeTaxProvisionDetail" id="IncomeTaxesSummaryOfComponentsOfIncomeTaxProvisionDetail">
<link:definition>1068 - Disclosure - Income Taxes - Summary of Components of Income Tax Provision (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/IncomeTaxesAdditionalInformationDetail" id="IncomeTaxesAdditionalInformationDetail">
<link:definition>1069 - Disclosure - Income Taxes - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/IncomeTaxesScheduleOfDifferencesBetweenEffectiveRateAndUnitedStatesFederalIncomeTaxStatutoryRateDetail" id="IncomeTaxesScheduleOfDifferencesBetweenEffectiveRateAndUnitedStatesFederalIncomeTaxStatutoryRateDetail">
<link:definition>1070 - Disclosure - Income Taxes - Schedule of Differences Between Effective Rate and United States Federal Income Tax Statutory Rate (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/IncomeTaxesSignificantComponentsOfDeferredIncomeTaxAssetsAndLiabilitiesDetail" id="IncomeTaxesSignificantComponentsOfDeferredIncomeTaxAssetsAndLiabilitiesDetail">
<link:definition>1071 - Disclosure - Income Taxes - Significant Components of Deferred Income Tax Assets and Liabilities (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/IncomeTaxesScheduleOfActivityRelatedToGrossUnrecognizedTaxBenefitsDetail" id="IncomeTaxesScheduleOfActivityRelatedToGrossUnrecognizedTaxBenefitsDetail">
<link:definition>1072 - Disclosure - Income Taxes - Schedule of Activity Related to Gross Unrecognized Tax Benefits (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/CommonAndCommonEquivalentSharesScheduleOfCalculationOfSharesUsedInBasicAndDilutedNetIncomePerShareDetail" id="CommonAndCommonEquivalentSharesScheduleOfCalculationOfSharesUsedInBasicAndDilutedNetIncomePerShareDetail">
<link:definition>1073 - Disclosure - Common and Common Equivalent Shares - Schedule of Calculation of Shares Used in Basic and Diluted Net Income Per Share (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/StockIncentivePlansAndStockPurchasePlansAdditionalInformationDetail" id="StockIncentivePlansAndStockPurchasePlansAdditionalInformationDetail">
<link:definition>1074 - Disclosure - Stock Incentive Plans and Stock Purchase Plans - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/StockIncentivePlansAndStockPurchasePlansScheduleOfRestrictedStockAndDeferredStockAwardsDetail" id="StockIncentivePlansAndStockPurchasePlansScheduleOfRestrictedStockAndDeferredStockAwardsDetail">
<link:definition>1075 - Disclosure - Stock Incentive Plans and Stock Purchase Plans - Schedule of Restricted Stock and Deferred Stock Awards (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/StockIncentivePlansAndStockPurchasePlansScheduleOfActivityAndCertainOtherInformationRelatedToStockOptionAwardsDetail" id="StockIncentivePlansAndStockPurchasePlansScheduleOfActivityAndCertainOtherInformationRelatedToStockOptionAwardsDetail">
<link:definition>1076 - Disclosure - Stock Incentive Plans and Stock Purchase Plans - Schedule of Activity and Certain Other Information Related to Stock Option Awards (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/CommonStockRepurchaseProgramsAdditionalInformationDetail" id="CommonStockRepurchaseProgramsAdditionalInformationDetail">
<link:definition>1077 - Disclosure - Common Stock Repurchase Programs - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/RetirementPlansAdditionalInformationDetail" id="RetirementPlansAdditionalInformationDetail">
<link:definition>1078 - Disclosure - Retirement Plans - Additional Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:roleType roleURI="http://www.mednax.com/role/SelectedQuarterlyFinancialInformationSummaryOfCompanysSelectedQuarterlyFinancialInformationDetail" id="SelectedQuarterlyFinancialInformationSummaryOfCompanysSelectedQuarterlyFinancialInformationDetail">
<link:definition>1079 - Disclosure - Selected Quarterly Financial Information - Summary of Company's Selected Quarterly Financial Information (Detail)</link:definition>
<link:usedOn>link:presentationLink</link:usedOn>
<link:usedOn>link:definitionLink</link:usedOn>
<link:usedOn>link:calculationLink</link:usedOn>
</link:roleType>
<link:linkbaseRef xlink:type="simple" xlink:href="md-20191231_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
<link:linkbaseRef xlink:type="simple" xlink:href="md-20191231_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
<link:linkbaseRef xlink:type="simple" xlink:href="md-20191231_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
<link:linkbaseRef xlink:type="simple" xlink:href="md-20191231_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
</appinfo>
</annotation>
<import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
<import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" />
<import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" />
<import namespace="http://fasb.org/us-gaap/2019-01-31" schemaLocation="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd" />
<import namespace="http://xbrl.sec.gov/country/2017-01-31" schemaLocation="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd" />
<import namespace="http://xbrl.sec.gov/currency/2019-01-31" schemaLocation="https://xbrl.sec.gov/currency/2019/currency-2019-01-31.xsd" />
<import namespace="http://xbrl.sec.gov/exch/2019-01-31" schemaLocation="https://xbrl.sec.gov/exch/2019/exch-2019-01-31.xsd" />
<import namespace="http://xbrl.sec.gov/naics/2017-01-31" schemaLocation="http://xbrl.sec.gov/naics/2017/naics-2017-01-31.xsd" />
<import namespace="http://xbrl.sec.gov/sic/2011-01-31" schemaLocation="http://xbrl.sec.gov/sic/2011/sic-2011-01-31.xsd" />
<import namespace="http://xbrl.sec.gov/stpr/2018-01-31" schemaLocation="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd" />
<import namespace="http://www.xbrl.org/2009/role/negated" schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" />
<import namespace="http://www.xbrl.org/2009/role/net" schemaLocation="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd" />
<import namespace="http://www.xbrl.org/2009/arcrole/fact-explanatoryFact" schemaLocation="http://www.xbrl.org/lrr/arcrole/factExplanatory-2009-12-16.xsd" />
<import namespace="http://xbrl.sec.gov/dei/2019-01-31" schemaLocation="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd" />
<import namespace="http://www.xbrl.org/dtr/type/numeric" schemaLocation="http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd" />
<import namespace="http://www.xbrl.org/dtr/type/non-numeric" schemaLocation="http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd" />
<import namespace="http://fasb.org/us-types/2019-01-31" schemaLocation="http://xbrl.fasb.org/us-gaap/2019/elts/us-types-2019-01-31.xsd" />
<import namespace="http://fasb.org/srt/2019-01-31" schemaLocation="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd" />
<import namespace="http://fasb.org/srt-types/2019-01-31" schemaLocation="http://xbrl.fasb.org/srt/2019/elts/srt-types-2019-01-31.xsd" />
<element name="AccountsPayableAndAccruedLiabilitiesExcludingAccruedIncomeTaxesCurrent" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_AccountsPayableAndAccruedLiabilitiesExcludingAccruedIncomeTaxesCurrent" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="LongTermDebtAndCapitalLeaseObligationsExcludingLongTermLineOfCredit" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_LongTermDebtAndCapitalLeaseObligationsExcludingLongTermLineOfCredit" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="PracticeSalariesAndBenefits" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_PracticeSalariesAndBenefits" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="PracticeSuppliesAndOtherOperatingExpenses" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_PracticeSuppliesAndOtherOperatingExpenses" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="IncomelossFromContinuingOperationsPerBasicAndDilutedShareAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_IncomelossFromContinuingOperationsPerBasicAndDilutedShareAbstract" substitutionGroup="xbrli:item" />
<element name="StockIssuedDuringPeriodSharesRestrictedStockAcquisitionConsideration" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_StockIssuedDuringPeriodSharesRestrictedStockAcquisitionConsideration" substitutionGroup="xbrli:item" />
<element name="StockIssuedDuringPeriodSharesStockSwaps" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_StockIssuedDuringPeriodSharesStockSwaps" substitutionGroup="xbrli:item" />
<element name="StockIssuedDuringPeriodValueRestrictedStockAcquisitionConsideration" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_StockIssuedDuringPeriodValueRestrictedStockAcquisitionConsideration" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="StockIssuedDuringPeriodValueStockSwaps" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_StockIssuedDuringPeriodValueStockSwaps" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsDiscontinuedOperationsEndingBalance" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsDiscontinuedOperationsEndingBalance" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="AccountsReceivableAndNetRevenueDisclosureTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_AccountsReceivableAndNetRevenueDisclosureTextBlock" substitutionGroup="xbrli:item" />
<element name="CommonStockRepurchasesTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_CommonStockRepurchasesTextBlock" substitutionGroup="xbrli:item" />
<element name="CommonStockShareRepurchasesPolicyTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_CommonStockShareRepurchasesPolicyTextBlock" substitutionGroup="xbrli:item" />
<element name="ProfessionalLiabilityCoveragePolicyTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_ProfessionalLiabilityCoveragePolicyTextBlock" substitutionGroup="xbrli:item" />
<element name="RecentlyAdoptedAccountingPronouncementsPolicyTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_RecentlyAdoptedAccountingPronouncementsPolicyTextBlock" substitutionGroup="xbrli:item" />
<element name="FinancialInstrumentsMeasuredAtCarryingAmountTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_FinancialInstrumentsMeasuredAtCarryingAmountTableTextBlock" substitutionGroup="xbrli:item" />
<element name="OperatingLeaseRelatedAssetsAndLiabilitiesAndOtherRelatedInformationTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_OperatingLeaseRelatedAssetsAndLiabilitiesAndOtherRelatedInformationTableTextBlock" substitutionGroup="xbrli:item" />
<element name="OperatingLeasesCashFlowRelatedInformationTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_OperatingLeasesCashFlowRelatedInformationTableTextBlock" substitutionGroup="xbrli:item" />
<element name="ScheduleOfAccruedProfessionalLiabilityTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_ScheduleOfAccruedProfessionalLiabilityTableTextBlock" substitutionGroup="xbrli:item" />
<element name="SummaryOfEstimatedFairValueOfNotesTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_SummaryOfEstimatedFairValueOfNotesTableTextBlock" substitutionGroup="xbrli:item" />
<element name="ScheduleOfFinanceLeaseObligationsTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_ScheduleOfFinanceLeaseObligationsTableTextBlock" substitutionGroup="xbrli:item" />
<element name="SummaryOfSignificantAccountingPoliciesTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_SummaryOfSignificantAccountingPoliciesTable" substitutionGroup="xbrldt:hypercubeItem" />
<element name="UnnamedCorporateJointVentureOneMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_UnnamedCorporateJointVentureOneMember" substitutionGroup="xbrli:item" />
<element name="UnnamedCorporateJointVentureTwoMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_UnnamedCorporateJointVentureTwoMember" substitutionGroup="xbrli:item" />
<element name="SummaryOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_SummaryOfSignificantAccountingPoliciesLineItems" substitutionGroup="xbrli:item" />
<element name="BusinessCombinationContingentConsiderationArrangementsTimePeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_BusinessCombinationContingentConsiderationArrangementsTimePeriod" substitutionGroup="xbrli:item" />
<element name="CashAndCashEquivalentsMaturityDescription" type="xbrli:stringItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_CashAndCashEquivalentsMaturityDescription" substitutionGroup="xbrli:item" />
<element name="ShortTermInvestmentMaturityPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_ShortTermInvestmentMaturityPeriod" substitutionGroup="xbrli:item" />
<element name="DivestitureOfBusinessesContingentConsiderationReceivableInEquityShares" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_DivestitureOfBusinessesContingentConsiderationReceivableInEquityShares" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="RegulatoryAssetsAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_RegulatoryAssetsAbstract" substitutionGroup="xbrli:item" />
<element name="SalesAndRevenueServicesNetMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_SalesAndRevenueServicesNetMember" substitutionGroup="xbrli:item" />
<element name="NeonatologyAndOtherPediatricSubspecialtiesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_NeonatologyAndOtherPediatricSubspecialtiesMember" substitutionGroup="xbrli:item" />
<element name="RadiologyAndTeleradiologyMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_RadiologyAndTeleradiologyMember" substitutionGroup="xbrli:item" />
<element name="AnesthesiologyAndRelatedMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_AnesthesiologyAndRelatedMember" substitutionGroup="xbrli:item" />
<element name="MoneyMarketFundsFairValueDisclosure" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_MoneyMarketFundsFairValueDisclosure" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="CompanyOwnedLifeInsuranceFairValueDisclosure" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_CompanyOwnedLifeInsuranceFairValueDisclosure" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="MutualFundsFairValueDisclosure" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_MutualFundsFairValueDisclosure" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="BusinessCombinationContingentConsiderationLiabilityFairValueDisclosure" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_BusinessCombinationContingentConsiderationLiabilityFairValueDisclosure" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="ShortTermInvestmentsFairValueDisclosure" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_ShortTermInvestmentsFairValueDisclosure" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="LongTermInvestmentsFairValueDisclosure" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_LongTermInvestmentsFairValueDisclosure" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="TwoThousandTwentyThreeMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_TwoThousandTwentyThreeMember" substitutionGroup="xbrli:item" />
<element name="TwoThousandTwentySevenMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_TwoThousandTwentySevenMember" substitutionGroup="xbrli:item" />
<element name="HospitalsContractsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_HospitalsContractsMember" substitutionGroup="xbrli:item" />
<element name="ScheduleOfFinancingReceivablesLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_ScheduleOfFinancingReceivablesLineItems" substitutionGroup="xbrli:item" />
<element name="PercentageOfNetPatientServiceRevenueByTypeOfPayor" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_PercentageOfNetPatientServiceRevenueByTypeOfPayor" substitutionGroup="xbrli:item" />
<element name="ContractedManagedCareMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_ContractedManagedCareMember" substitutionGroup="xbrli:item" />
<element name="PropertyPlantAndEquipmentCapitalizedInterestCostsAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_PropertyPlantAndEquipmentCapitalizedInterestCostsAbstract" substitutionGroup="xbrli:item" />
<element name="NumberOfPhysicianGroupPracticesAcquired" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_NumberOfPhysicianGroupPracticesAcquired" substitutionGroup="xbrli:item" />
<element name="NumberOfNeonatologyPracticesAcquired" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_NumberOfNeonatologyPracticesAcquired" substitutionGroup="xbrli:item" />
<element name="NumberOfPediatricSubspecialtyPracticesAcquired" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_NumberOfPediatricSubspecialtyPracticesAcquired" substitutionGroup="xbrli:item" />
<element name="NumberOfRadiologyPracticesAcquired" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_NumberOfRadiologyPracticesAcquired" substitutionGroup="xbrli:item" />
<element name="NumberOfMaternalfetalMedicinePracticesAcquired" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_NumberOfMaternalfetalMedicinePracticesAcquired" substitutionGroup="xbrli:item" />
<element name="AccruedPurchaseConsideration" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_AccruedPurchaseConsideration" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="PaymentForPurchaseConsiderationRelatedToPriorPeriodAcquisitions" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_PaymentForPurchaseConsiderationRelatedToPriorPeriodAcquisitions" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="PhysicianGroupMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_PhysicianGroupMember" substitutionGroup="xbrli:item" />
<element name="PriorPeriodAcquisitionsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_PriorPeriodAcquisitionsMember" substitutionGroup="xbrli:item" />
<element name="PhysicianAndHospitalAgreementsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_PhysicianAndHospitalAgreementsMember" substitutionGroup="xbrli:item" />
<element name="GoodwillAndOtherIntangibleAssetsLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_GoodwillAndOtherIntangibleAssetsLineItems" substitutionGroup="xbrli:item" />
<element name="GoodwillRecognitionOfDeferredTaxAsset" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_GoodwillRecognitionOfDeferredTaxAsset" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="GoodwillIncrementalImpairmentCharges" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_GoodwillIncrementalImpairmentCharges" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="AnaesthesiologyReportingUnitMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_AnaesthesiologyReportingUnitMember" substitutionGroup="xbrli:item" />
<element name="PatentedAndOtherTechnologyMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_PatentedAndOtherTechnologyMember" substitutionGroup="xbrli:item" />
<element name="NetProceedsForTheManagementServicesServiceLine" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_NetProceedsForTheManagementServicesServiceLine" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="DeferredTaxAssetsAxis" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_DeferredTaxAssetsAxis" substitutionGroup="xbrldt:dimensionItem" />
<element name="DeferredTaxAssetsDomain" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_DeferredTaxAssetsDomain" substitutionGroup="xbrli:item" />
<element name="DeferredTaxAssetsGoodwillMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_DeferredTaxAssetsGoodwillMember" substitutionGroup="xbrli:item" />
<element name="DeferredTaxAssetsIntangibleAssetsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_DeferredTaxAssetsIntangibleAssetsMember" substitutionGroup="xbrli:item" />
<element name="AccruedContingentConsiderationLiabilityCurrent" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_AccruedContingentConsiderationLiabilityCurrent" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="AccruedPayrollTaxesAndBenefitsCurrent" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_AccruedPayrollTaxesAndBenefitsCurrent" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="OperatingLeasesAssetsAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_OperatingLeasesAssetsAbstract" substitutionGroup="xbrli:item" />
<element name="OperatingLeasesLiabilitiesAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_OperatingLeasesLiabilitiesAbstract" substitutionGroup="xbrli:item" />
<element name="OtherInformationRelatedToOperatingLeaseAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_OtherInformationRelatedToOperatingLeaseAbstract" substitutionGroup="xbrli:item" />
<element name="OperatingLeasesOtherCosts" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_OperatingLeasesOtherCosts" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="OtherEquipmentRent" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_OtherEquipmentRent" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="AccruedProfessionalLiability" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_AccruedProfessionalLiability" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="AccruedProfessionalLiabilitiesAssumedThroughAcquisition" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_AccruedProfessionalLiabilitiesAssumedThroughAcquisition" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="MalpracticeLossContingencyProvisionForLosses" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_MalpracticeLossContingencyProvisionForLosses" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="ProvisionAdjustmentForLossesRelatedToCurrentYear" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_ProvisionAdjustmentForLossesRelatedToCurrentYear" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="ProvisionAdjustmentForLossesRelatedToPriorYear" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_ProvisionAdjustmentForLossesRelatedToPriorYear" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="FivePointTwoFivePercentSeniorUnsecuredNotesDueTwoThousandTwentyThreeMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_FivePointTwoFivePercentSeniorUnsecuredNotesDueTwoThousandTwentyThreeMember" substitutionGroup="xbrli:item" />
<element name="SixPointTwoFivePercentSeniorUnsecuredNotesDueTwoThousandTwentySevenMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_SixPointTwoFivePercentSeniorUnsecuredNotesDueTwoThousandTwentySevenMember" substitutionGroup="xbrli:item" />
<element name="UnsecuredRevolvingCreditFacilityMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_UnsecuredRevolvingCreditFacilityMember" substitutionGroup="xbrli:item" />
<element name="AlternateBaseRateMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_AlternateBaseRateMember" substitutionGroup="xbrli:item" />
<element name="ApplicableMarginRateMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_ApplicableMarginRateMember" substitutionGroup="xbrli:item" />
<element name="DebtInstrumentMaturityYear" type="xbrli:gYearItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_DebtInstrumentMaturityYear" substitutionGroup="xbrli:item" />
<element name="DebtInstrumentRedemptionPeriodBeforeTwoThousandTwentyTwoMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_DebtInstrumentRedemptionPeriodBeforeTwoThousandTwentyTwoMember" substitutionGroup="xbrli:item" />
<element name="DebtInstrumentRedemptionPeriodSixAndThereafterMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_DebtInstrumentRedemptionPeriodSixAndThereafterMember" substitutionGroup="xbrli:item" />
<element name="DebtInstrumentRedemptionPeriodThreeAndThereafterMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_DebtInstrumentRedemptionPeriodThreeAndThereafterMember" substitutionGroup="xbrli:item" />
<element name="ChangeInControlMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_ChangeInControlMember" substitutionGroup="xbrli:item" />
<element name="RedeemUpToThirtyFivePercentageOfAggregatePrincipalAmountMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_RedeemUpToThirtyFivePercentageOfAggregatePrincipalAmountMember" substitutionGroup="xbrli:item" />
<element name="DebtInstrumentFairValueTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_DebtInstrumentFairValueTable" substitutionGroup="xbrldt:hypercubeItem" />
<element name="DebtInstrumentFairValueLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_DebtInstrumentFairValueLineItems" substitutionGroup="xbrli:item" />
<element name="IncomeTaxTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_IncomeTaxTable" substitutionGroup="xbrldt:hypercubeItem" />
<element name="IncomeTaxLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_IncomeTaxLineItems" substitutionGroup="xbrli:item" />
<element name="IncomeTaxExpenseForExcessTaxDeficiencies" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_IncomeTaxExpenseForExcessTaxDeficiencies" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="NetOperatingLossCarryForwardsExpirationDate" type="xbrli:gYearItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_NetOperatingLossCarryForwardsExpirationDate" substitutionGroup="xbrli:item" />
<element name="CapitalLossesIncurred" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_CapitalLossesIncurred" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="CapitalLossCarryforwardsExpirationDate" type="us-types:gYearListItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_CapitalLossCarryforwardsExpirationDate" substitutionGroup="xbrli:item" />
<element name="CapitalLossCarryforwardsValuationAllowance" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_CapitalLossCarryforwardsValuationAllowance" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="EffectiveIncomeTaxReconciliationCapitalLossOnLiquidationPercentage" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="md_EffectiveIncomeTaxReconciliationCapitalLossOnLiquidationPercentage" substitutionGroup="xbrli:item" />
<element name="DeferredTaxLiabilitiesChangeInAccountingMethod" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_DeferredTaxLiabilitiesChangeInAccountingMethod" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="DeferredTaxAssetsTotalLossCarryforwards" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="md_DeferredTaxAssetsTotalLossCarryforwards" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="RestrictedAndDeferredStockUnitsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_RestrictedAndDeferredStockUnitsMember" substitutionGroup="xbrli:item" />
<element name="AmendedAndRestatedTwoThousandEightPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_AmendedAndRestatedTwoThousandEightPlanMember" substitutionGroup="xbrli:item" />
<element name="NineteenNinetySixNonQualifiedEmployeeStockPurchasePlanAndTwoThousandFifteenNonQualifiedStockPurchasePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_NineteenNinetySixNonQualifiedEmployeeStockPurchasePlanAndTwoThousandFifteenNonQualifiedStockPurchasePlanMember" substitutionGroup="xbrli:item" />
<element name="NineteenNinetySixNonQualifiedEmployeeStockPurchasePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_NineteenNinetySixNonQualifiedEmployeeStockPurchasePlanMember" substitutionGroup="xbrli:item" />
<element name="TwoThousandFifteenNonQualifiedStockPurchasePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_TwoThousandFifteenNonQualifiedStockPurchasePlanMember" substitutionGroup="xbrli:item" />
<element name="CommonStockTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_CommonStockTable" substitutionGroup="xbrldt:hypercubeItem" />
<element name="CommonStockLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="md_CommonStockLineItems" substitutionGroup="xbrli:item" />
</schema>
