<SEC-DOCUMENT>0000856982-18-000056.txt : 20180615
<SEC-HEADER>0000856982-18-000056.hdr.sgml : 20180615
<ACCEPTANCE-DATETIME>20180615152453
ACCESSION NUMBER:		0000856982-18-000056
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180613
FILED AS OF DATE:		20180615
DATE AS OF CHANGE:		20180615

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Wright Joseph
		CENTRAL INDEX KEY:			0001643713

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-18592
		FILM NUMBER:		18902017

	MAIL ADDRESS:	
		STREET 1:		1600 WEST MERIT PARKWAY
		CITY:			SOUTH JORDAN
		STATE:			UT
		ZIP:			84095

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MERIT MEDICAL SYSTEMS INC
		CENTRAL INDEX KEY:			0000856982
		STANDARD INDUSTRIAL CLASSIFICATION:	SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
		IRS NUMBER:				870447695
		STATE OF INCORPORATION:			UT
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1600 WEST MERIT PARK WAY
		CITY:			SOUTH JORDAN
		STATE:			UT
		ZIP:			84095
		BUSINESS PHONE:		8012531600

	MAIL ADDRESS:	
		STREET 1:		1600 WEST MERIT PARKWAY
		CITY:			SOUTH JORDAN
		STATE:			UT
		ZIP:			84095
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_152909067638094.xml
<DESCRIPTION>FORM 4
<TEXT>
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    <periodOfReport>2018-06-13</periodOfReport>

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    <issuer>
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        <issuerName>MERIT MEDICAL SYSTEMS INC</issuerName>
        <issuerTradingSymbol>MMSI</issuerTradingSymbol>
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            <rptOwnerName>Wright Joseph</rptOwnerName>
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            <rptOwnerStreet2></rptOwnerStreet2>
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            <rptOwnerZipCode>84095</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
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            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, International</officerTitle>
            <otherText></otherText>
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                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                <transactionPricePerShare>
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    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
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            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-06-13</value>
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            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                    <value>9928</value>
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                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
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            <exerciseDate>
                <value>2012-08-11</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-08-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>9928.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10072</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.75</value>
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            <transactionDate>
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            </transactionDate>
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                <transactionFormType>4</transactionFormType>
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            <transactionAmounts>
                <transactionShares>
                    <value>10072</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2012-08-11</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-08-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10072.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
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        <derivativeHolding>
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            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2014-07-31</value>
                <footnoteId id="F4"/>
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            <expirationDate>
                <value>2020-07-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000.0</value>
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            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
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                <footnoteId id="F5"/>
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            <expirationDate>
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        <derivativeHolding>
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                <footnoteId id="F6"/>
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            <expirationDate>
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            <underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
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        <derivativeHolding>
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            <exerciseDate>
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                <footnoteId id="F7"/>
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            </expirationDate>
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                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
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        <derivativeHolding>
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                <value>Non-qualified stock options (right to buy)</value>
            </securityTitle>
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                <value>28.2</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2018-04-14</value>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2024-04-14</value>
            </expirationDate>
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                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
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            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2019-03-02</value>
                <footnoteId id="F9"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-03-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 of Table 1 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $49.45 to $49.58, inclusive. The Reporting Person undertakes to provide to Merit Medical Systems, Inc., any security holder of Merit Medical Systems, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.</footnote>
        <footnote id="F2">The price reported in Column 4 of Table 1 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $49.55 to $49.65, inclusive. The Reporting Person undertakes to provide to Merit Medical Systems, Inc., any security holder of Merit Medical Systems, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.</footnote>
        <footnote id="F3">Becomes exercisable in equal annual installments of 20% commencing on 08/11/2012.</footnote>
        <footnote id="F4">Becomes exercisable in equal annual installments of 20% commencing on 07/31/2014.</footnote>
        <footnote id="F5">Becomes exercisable in equal annual installments of 20% commencing on 10/04/2015.</footnote>
        <footnote id="F6">Becomes exercisable in equal annual installments of 20% commencing on 02/13/2016.</footnote>
        <footnote id="F7">Becomes exercisable in equal annual installments of 20% commencing on 01/28/2017.</footnote>
        <footnote id="F8">Becomes exercisable in equal annual installments of 20% commencing on 04/14/2018.</footnote>
        <footnote id="F9">Becomes exercisable in equal annual installments of 20% commencing on 03/02/2019.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Brian G. Lloyd, Attorney-in-Fact</signatureName>
        <signatureDate>2018-06-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
