1. Summary of Significant Accounting Policies

Terms Used in Notes to Consolidated Financial Statements

ASC - Accounting Standards Codification.

ASC Topic 606 - ASU No. 2014-09, Revenue from Contracts with Customers.

ASU - Accounting Standards Update.

FASB - The Financial Accounting Standards Board.

GAAP - U.S. generally accepted accounting principles.

IRC - Internal Revenue Code.

IRS - Internal Revenue Service.

Underwriting enterprises - Insurance companies, reinsurance companies and various other forms of risk-taking entities, including intermediaries of underwriting enterprises.

VIE - Variable interest entity.

Nature of Operations and Basis of Presentation

Arthur J. Gallagher & Co. and its subsidiaries, collectively referred to herein as we, our, us or the company, provide insurance brokerage, consulting and third party claims settlement and administration services to both domestic and international entities through three reportable operating segments. Our brokers, agents and administrators act as intermediaries between underwriting enterprises and our clients.

Our brokerage segment operations provide brokerage and consulting services to companies and entities of all types, including commercial, not-for-profit, and public entities, and, to a lesser extent, individuals, in the areas of insurance placement, risk of loss management, and management of employer sponsored benefit programs. Our risk management segment operations provide contract claim settlement, claim administration, loss control services and risk management consulting for commercial, not-for-profit, captive and public entities, and various other organizations that choose to self-insure property/casualty coverages or choose to use a third-party claims management organization rather than the claim services provided by underwriting enterprises. The corporate segment reports the financial information related to our debt, clean energy investments, external acquisition-related expenses and other corporate costs. Clean energy investments consist of our investments in limited liability companies that own 34 commercial clean coal production facilities producing refined coal using Chem-Mod LLC’s proprietary technologies. We believe these operations produce refined coal that qualifies for tax credits under IRC Section 45.

We do not assume underwriting risk on a net basis, other than with respect to de minimis amounts necessary to provide minimum or regulatory capital to organize captives, pools, specialized underwriters or risk-retention groups. Rather, capital necessary for events of loss coverages is provided by underwriting enterprises.

Investment income and other revenues are generated from our premium financing operations and our investment portfolio, which includes our invested cash and restricted cash we hold on behalf of our clients, as well as clean energy investments.

We are headquartered in Rolling Meadows, Illinois, have operations in 33 countries and offer client-service capabilities in more than 150 countries globally through a network of correspondent insurance brokers and consultants.

We have prepared the accompanying unaudited consolidated financial statements pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures normally included in annual financial statements have been omitted pursuant to such rules and regulations. The unaudited consolidated financial statements included herein are, in the opinion of management, prepared on a basis consistent with our audited consolidated financial statements for the year ended December 31, 2017, except as disclosed in Note 2, and include all normal recurring adjustments necessary for a fair presentation of the information set forth. The quarterly results of operations are not necessarily indicative of the results of operations to be reported for subsequent quarters or the full year. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2017. In the preparation of our unaudited consolidated financial statements as of March 31, 2018, management evaluated all material subsequent events or transactions that occurred after the balance sheet date through the date on which the financial statements were issued, for potential recognition or disclosure therein.

Use of Estimates

The preparation of our consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. These accounting principles require us to make estimates and assumptions that affect the reported amounts of assets and liabilities and revenues and expenses, and the disclosure of contingent assets and liabilities at the date of our consolidated financial statements. We are also required to make certain judgments and estimates that affect the disclosed and recorded amounts of revenues and expenses related to the impact of the adoption of and accounting under ASC Topic 606. We periodically evaluate our estimates and assumptions, including those relating to the valuation of goodwill and other intangible assets, investments (including our IRC Section 45 investments), income taxes, revenue recognition, deferred costs, stock-based compensation, claims handling obligations, retirement plans, litigation and contingencies. We base our estimates on historical experience and various assumptions that we believe to be reasonable based on specific circumstances. Such estimates and assumptions could change in the future as more information becomes known, which could impact the amounts reported and disclosed herein.

Revenue Recognition

Our revenues are derived from commissions and fees as primarily specified in a written contract, or unwritten business understanding, with our clients or underwriting enterprises. We also recognize investment income over time from our invested assets and invested assets we hold on behalf of our clients or underwriting enterprises.

BROKERAGE SEGMENT

Our brokerage segment generates revenues by:

(i)

Identifying, negotiating and placing all forms of insurance or reinsurance coverage, as well as providing risk-shifting, risk-sharing and risk-mitigation consulting services, principally related to property/casualty, life, health, welfare and disability insurance. We also provide these services through, or in conjunction with, other unrelated agents and brokers, consultants and management advisors.

(ii)

Acting as an agent or broker for multiple underwriting enterprises by providing services such as sales, marketing, selecting, negotiating, underwriting, servicing and placing insurance coverage on their behalf.

(iii)

Providing consulting services related to health and welfare benefits, voluntary benefits, executive benefits, compensation, retirement planning, institutional investment and fiduciary, actuarial, compliance, private insurance exchange, human resource technology, communications and benefits administration.

(iv)

Providing management and administrative services to captives, pools, risk-retention groups, healthcare exchanges, small underwriting enterprises, such as accounting, claims and loss processing assistance, feasibility studies, actuarial studies, data analytics and other administrative services.

The majority of our brokerage contracts and service understandings are for a period of one year or less.

Commissions and fees

The primary source of revenues for our brokerage services are commissions from underwriting enterprises, based on a percentage of premiums paid by our clients, or fees received from clients based on an agreed level of service usually in lieu of commissions.

Commissions are fixed at the contract effective date and generally are based on a percentage of premiums for insurance coverage or employee head count for employer sponsored benefit plans. Commissions depend upon a large number of factors, including the type of risk being placed, the particular underwriting enterprise’s demand, the expected loss experience of the particular risk of coverage, and historical benchmarks surrounding the level of effort necessary for us to place and service the insurance contract. Rather than being tied to the amount of premiums, fees are most often based on an expected level of effort to provide our services.

Whether we are paid a commission or a fee, the vast majority of our services are associated with the placement of an insurance (or insurance-like) contract. Accordingly, we recognize approximately 70% of our commission and fee revenues on the effective date of the underlying insurance contract. The amount of revenue we recognize is based on our costs to provide our services up and through that effective date, including an appropriate estimate of our profit margin on a portfolio basis (a practical expedient as defined in ASC Topic 606). Based on the proportion of additional services we provide in each period after the effective date of the insurance contract, including an appropriate estimate of our profit margin, we recognize approximately 20% of our commission and fee revenues in the first three months, and the remaining 10% thereafter. These periods may be different than the underlying premium payment patterns of the insurance contracts, but the vast majority of our services are fully provided within one year of the insurance contract effective date.

For consulting and advisory services, we recognize our revenue in the period in which we provide the service or advice. For management and administrative services, our revenue is recognized ratably over the contract period consistent with the performance of our obligations, mostly over an annual term.

Supplemental revenues

Certain underwriting enterprises may pay us additional revenues for the volume of premium placed with them and for insights into our sales pipeline, our sales capabilities or our risk selection knowledge. These amounts are in excess of the commission and fee revenues discussed above, and not all business we place with underwriting enterprises is eligible for supplemental revenues. Unlike contingent revenues, discussed below, these revenues are a fixed amount or fixed percentage of premium of the underlying eligible insurance contracts. For supplemental revenue contracts based on a fixed percentage of premium, our obligation to the underwriting enterprise is substantially completed upon the effective date of the underlying insurance contract and revenue is fully earned at that time. For supplemental revenue contracts based on a fixed amount, revenue is recognized ratably over the contract period consistent with the performance of our obligations, almost always over an annual term. We receive these revenues on a quarterly or annual basis.

Contingent revenues

Certain underwriting enterprises may pay us additional revenues for our sales capabilities, our risk selection knowledge, or our administrative efficiencies. These amounts are in excess of the commission or fee revenues discussed above, and not all business we place with participating underwriting enterprises is eligible for contingent revenues. Unlike supplemental revenues, also discussed above, these revenues are variable, generally based on growth, the loss experience of the underlying insurance contracts, and/or our efficiency in processing the business. We generally operate under calendar year contracts, but we do not receive these revenues from the underwriting enterprises until the following calendar year, generally in the first and second quarters, after verification of the performance indicators outlined in the contracts. Accordingly, during each reporting period, we must make our best estimate of amounts we have earned using historical averages and other factors to project such revenues. We base our estimates each period on a contract-by-contract basis where available. In certain cases, it is impractical to assess a very large number of smaller contingent revenue contracts, so we use a historical portfolio estimate in aggregate (a practical expedient as defined in ASC Topic 606). Because our expectation of the ultimate contingent revenue amounts to be earned can vary from period to period, especially in contracts sensitive to loss ratios, our estimates might change significantly from quarter to quarter. For example, in circumstances where our revenues are dependent on a full calendar year loss ratio, adverse loss experience in the fourth quarter could not only negate revenue earnings in the fourth quarter, but also trigger the need to reverse revenues previously recognized during the prior quarters. Variable consideration is recognized when we conclude, based on all the facts and information available at the reporting date, that is it probable that a significant revenue reversal will not occur in future periods.

Sub-brokerage costs

Sub-brokerage costs are excluded from our gross revenues in our determination of total revenues. Sub-brokerage cost represents commissions paid to sub-brokers related to the placement of certain business by our brokerage segment operations. We recognize this contra revenue in the same manner as the commission revenue it relates to.

RISK MANAGEMENT SEGMENT

Revenues for our risk management segment are comprised of fees generally negotiated (i) on a per-claim basis, (ii) on a cost-plus basis, or (iii) as performance-based fees. We also provide risk management consulting services that are recognized as the services are delivered.

Per-claim fees

Where we operate under a contract with our fee established on a per claim basis, our obligation is to process claims for a term specified within the contract. Because it is impractical to recognize our revenues on an individual claim by claim basis, we recognize revenue plus an appropriate estimate of our profit margin on a portfolio basis by grouping claims with similar characteristics (a practical expedient as defined in ASC Topic 606). We apply actuarially-determined, historical-based patterns to determine our future service obligations, without applying a present value discount.

Cost-plus fees

Where we provide services and generate revenues on a cost-plus basis, we recognize revenue over the contract period consistent with the performance of our obligations.

Performance-based fees

Certain clients pay us additional fee revenues for our efficiency in managing claims or on the basis of claim outcome effectiveness. These amounts are in excess of the fee revenues discussed above. These revenues are variable, generally based on performance metrics set forth in the underlying contracts. We generally operate under multi-year contracts with fiscal year measurement periods. We do not receive these fees, if earned, until the following year after verification of the performance metrics outlined in the contracts. Each period we base our estimates on a contract-by-contractbasis. We must make our best estimate of amounts we have earned using historical averages and other factors to project such revenues. Variable consideration is recognized when we conclude that is it probable that a significant revenue reversal will not occur in future periods.

Reimbursements

Reimbursement represent amounts received from clients reimbursing us for certain third-party costs associated with providing our claims management services. In certain service partner relationships, we are considered a principal because we direct the third party, control the specified service and combine the services provided into an integrated solution. Given this principal relationship, we are required to recognize revenue gross and service partner vendor fees in the operating expense in our consolidated statement of earnings.

Deferred Costs

We incur costs to provide brokerage and risk management services. Those costs are either (i) costs to obtain a contract or (ii) costs to fulfill such contract, or (iii) all other costs.

(i)

Costs to obtain - we incur costs to obtain a contract with a client. Those costs would not have been incurred if the contract had not been obtained. Almost all of our costs to obtain are incurred prior to, or on, the effective date of the contract and consist primarily of incentive compensation we pay to our production employees. Our costs to obtain are expensed as incurred as described in Note 3 to these unaudited consolidated financial statements.

(ii)

Costs to fulfill - we incur costs to fulfill a contract (or anticipated contract) with a client. Those costs are incurred prior to the effective date of the contract and relate to fulfilling our primary placement obligations to our clients. Our costs to fulfil prior to the effective date are capitalized and amortized on the effective date. These fulfilment activities include collecting underwriting information from our client, assessing their insurance needs and negotiating their placement with one or more underwriting enterprises. The majority of costs that we incur relate to compensation and benefits of our client service employees. Costs incurred during preplacement activities are expected to be recovered in the future. If the capitalized costs are no longer deemed to be recoverable, then they would be expensed.

(iii)

Other costs that are not costs to obtain or fulfill are expensed as incurred. Examples include other operating costs such as rent, utilities, management costs, overhead costs, legal and other professional fees, technology costs, insurance related costs, communication and advertising, and travel and entertainment. Depreciation, amortization and change in estimated acquisition earnout payable are expensed as incurred.