UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

For the quarterly period ended March 31, 2016

or

For the transition period from             to             

Commission File Number: 1-09761

ARTHUR J. GALLAGHER & CO.

(Exact name of registrant as specified in its charter)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15 (d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.     Yes  x     No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).     Yes  x     No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨     No  x

The number of outstanding shares of the registrant’s common stock, $1.00 par value, as of March 31, 2016 was approximately 177,129,000.

Arthur J. Gallagher & Co.

Index

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Part I - Financial Information

Item 1. Financial Statements (Unaudited)

Arthur J. Gallagher & Co.

Consolidated Statement of Earnings

(Unaudited - in millions, except per share data)

See notes to consolidated financial statements.

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Arthur J. Gallagher & Co.

Consolidated Statement of Comprehensive Earnings

(Unaudited - in millions)

See notes to consolidated financial statements.

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Arthur J. Gallagher & Co.

Consolidated Balance Sheet

(In millions)

See notes to consolidated financial statements.

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Arthur J. Gallagher & Co.

Consolidated Statement of Cash Flows

(Unaudited - in millions)

See notes to consolidated financial statements.

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Arthur J. Gallagher & Co.

Consolidated Statement of Stockholders’ Equity

(Unaudited - in millions)

See notes to consolidated financial statements.

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Notes to March 31, 2016 Consolidated Financial Statements (Unaudited)

1. 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 and risk management services to a wide variety of commercial, industrial, institutional and governmental organizations through three reportable operating segments. Commission and fee revenue generated by the brokerage segment is primarily related to the negotiation and placement of insurance for our clients. Fee revenue generated by the risk management segment is primarily related to claims management, information management, risk control consulting (loss control) services and appraisals in the property/casualty market. Investment income and other revenue are generated from our premium financing operations and our investment portfolio, which includes invested cash and restricted funds, as well as clean energy and other investments. We are headquartered in Itasca, Illinois, have operations in 31 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, 2015, 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, 2015. In the preparation of our unaudited consolidated financial statements as of March 31, 2016, 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.

2. Effect of New Accounting Pronouncements

Stock Compensation

In March 2016, the Financial Accounting Standards Board (which we refer to as the FASB) issued Accounting Standards Update (which we refer to as ASU) No. 2016-09, Improvements to Employee Share-Based Payment Accounting. This new accounting guidance requires that all companies recognize the income tax effects of awards in the income statement when the awards vest or are settled, rather than maintaining an APIC pool and recognizing the tax benefits in excess of compensation costs through equity. As it relates to forfeitures, the guidance allows for companies to choose whether to continue to estimate forfeitures or account for forfeitures as they occur. ASU 2016-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted and the new guidance may be applied either retrospectively or on a prospective basis. Management is currently reviewing the guidance, and the impact from its adoption on our consolidated financial statements cannot be determined at this time.

Consolidations

In February 2015, the FASB issued ASU No. 2015-02, Amendments to the Consolidation Analysis. This new accounting guidance on consolidations, eliminates the deferral granted to investment companies from applying the variable interest entities guidance and makes targeted amendments to the current consolidation guidance. The new guidance applies to all entities involved with limited partnerships or similar entities and required re-evaluation of these entities under the revised guidance, which could have changed previous consolidation conclusions. The new guidance was effective in first quarter of 2016 and has been applied by us. The adoption of this guidance did not have a material impact on our consolidated financial statements.

Debt Issuance Costs

In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. The new accounting guidance requires debt issuance costs to be presented in the balance sheet as a direct deduction from the associated debt liability. The new guidance was effective in first quarter 2016 and has been applied by us on a retrospective basis. Accordingly, we have reclassified debt issuance costs of $3.3 million previously included in Other non-current assets to Corporate related borrowings – noncurrent in our consolidated balance sheet as of December 31, 2015.

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Intangibles – Goodwill and Other

In April 2015, the FASB issued ASU No. 2015-05, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. This new guidance provides additional information to help entities determine whether a cloud computing arrangement contains a software license that should be accounted for as internal-use software or as a service contract. The new guidance was effective in first quarter 2016 and has been applied by us. The adoption of this guidance did not have a material impact on our consolidated financial statements.

Business Combinations

In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. The new accounting guidance requires that measurement period adjustments be recognized in the reporting period in which the adjustment amount is determined rather than retrospectively applying the change to the acquisition date. The new guidance was effective in first quarter 2016 and was applied by us. The adoption of this guidance did not have a material impact on our consolidated financial statements.

Income Taxes

In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. The new accounting guidance requires that deferred tax assets and liabilities be classified as noncurrent on the balance sheet rather than being separated into current and noncurrent components. ASU 2015-17 is effective in first quarter 2017. Early adoption is permitted and the standard may be applied either retrospectively or on a prospective basis to all deferred tax assets and liabilities. We early adopted ASU 2015-17 during first quarter 2016 on a retrospective basis. Accordingly, we reclassified the current deferred taxes to noncurrent in our December 31, 2015 consolidated balance sheet, which increased Noncurrent deferred tax assets by $122.1 million and increased Other noncurrent liabilities by $4.6 million.

Revenue Recognition

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, as a new Topic, ASC 606, which will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The core principal of the new accounting guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. On July 9, 2015, the FASB decided to delay the effective date of the new revenue standard by one year. Reporting entities may choose to adopt the standard as of the original effective date. The FASB decided, based on its outreach to various stakeholders and the forthcoming amendments to the new revenue standard, that a deferral was necessary to provide adequate time to effectively implement the new revenue standard. This new guidance was originally effective for the first quarter 2017 and early adoption was not permitted. With the one year deferral date, this new guidance is now effective for the first quarter 2018, but it can be adopted earlier in first quarter of 2017. The guidance permits two methods of transition upon adoption; full retrospective and modified retrospective. Under the full retrospective method, prior periods would be restated under the new revenue standard, providing a comparable view across all periods presented. Under the modified retrospective method, prior periods would not be restated. Rather, revenues and other disclosures for pre-2017 periods would be provided in the notes to the financial statements as previously reported under the current revenue standard. We are currently reviewing the guidance, and the impact from its adoption on our consolidated financial statements cannot be determined at this time.

Leases

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). Under this new accounting guidance, an entity is required to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. This new guidance offers specific accounting guidance for a lessee, a lessor and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. This new guidance is effective for first quarter 2019, and requires a modified retrospective adoption, with early adoption permitted. We are currently reviewing the new guidance, and the impact from its adoption on our consolidated financial statements cannot be determined at this time.

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3. Business Combinations

During the three-month period ended March 31, 2016, we acquired substantially all of the net assets of the following firms in exchange for our common stock and/or cash. These acquisitions have been accounted for using the acquisition method for recording business combinations (in millions except share data):

Common shares issued in connection with acquisitions are valued at closing market prices as of the effective date of the applicable acquisition. We record escrow deposits that are returned to us as a result of adjustments to net assets acquired as reductions of goodwill when the escrows are settled. The maximum potential earnout payables disclosed in the foregoing table represent the maximum amount of additional consideration that could be paid pursuant to the terms of the purchase agreement for the applicable acquisition. The amounts recorded as earnout payables, which are primarily based upon the estimated future operating results of the acquired entities over a two- to three-year period subsequent to the acquisition date, are measured at fair value as of the acquisition date and are included on that basis in the recorded purchase price consideration in the foregoing table. We will record subsequent changes in these estimated earnout obligations, including the accretion of discount, in our consolidated statement of earnings when incurred. The fair value of these earnout obligations is based on the present value of the expected future payments to be made to the sellers of the acquired entities in accordance with the provisions outlined in the respective purchase agreements, which is a Level 3 fair value measurement. In determining fair value, we estimated the acquired entity’s future performance using financial projections developed by management for the acquired entity and market participant assumptions that were derived for revenue growth and/or profitability. Revenue growth rates generally ranged from 3.5% to 4.0% for our 2016 acquisitions. We estimated future payments using the earnout formula and performance targets specified in each purchase agreement and these financial projections. We then discounted these payments to present value using a risk-adjusted rate that takes into consideration market-based rates of return that reflect the ability of the acquired entity to achieve the targets. These discount rates generally ranged from 8.5% to 9.0% for all of our 2016 acquisitions. Changes in financial projections, market participant assumptions for revenue growth and/or profitability, or the risk-adjusted discount rate, would result in a change in the fair value of recorded earnout obligations.

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During the three-month periods ended March 31, 2016 and 2015, we recognized $4.2 million and $4.2 million, respectively, of expense in our consolidated statement of earnings related to the accretion of the discount recorded for earnout obligations in connection with our acquisitions. In addition, during the three-month periods ended March 31, 2016 and 2015, we recognized $0.3 million of income and $6.4 million of expense, respectively, related to net adjustments in the estimated fair value of earnout obligations in connection with revised projections of future performance for 32 and 24 acquisitions, respectively. The aggregate amount of maximum earnout obligations related to acquisitions was $530.2 million as of March 31, 2016, of which $213.4 million was recorded in our consolidated balance sheet as of March 31, 2016, based on the estimated fair value of the expected future payments to be made.

The following is a summary of the estimated fair values of the net assets acquired at the date of each acquisition made in the three-month period ended March 31, 2016 (in millions):

Among other things, these acquisitions allow us to expand into desirable geographic locations, further extend our presence in the retail and wholesale insurance brokerage services and risk management industries and increase the volume of general services currently provided. The excess of the purchase price over the estimated fair value of the tangible net assets acquired at the acquisition date was allocated to goodwill, expiration lists and non-compete agreements in the amounts of $33.5 million, $34.2 million and $1.6 million, respectively, within the brokerage segment.

Provisional estimates of fair value are established at the time of each acquisition and are subsequently reviewed within the first year of operations subsequent to the acquisition date to determine the necessity for adjustments. The fair value of the tangible assets and liabilities for each applicable acquisition at the acquisition date approximated their carrying values. The fair value of expiration lists was established using the excess earnings method, which is an income approach based on estimated financial projections developed by management for each acquired entity using market participant assumptions. Revenue growth and attrition rates generally ranged from 2.0% to 3.0% and 2.5% to 10.0%, respectively, for our 2015 acquisitions for which valuations were performed in 2016. We estimate the fair value as the present value of the benefits anticipated from ownership of the subject customer list in excess of returns required on the investment in contributory assets necessary to realize those benefits. The rate used to discount the net benefits was based on a risk-adjusted rate that takes into consideration market-based rates of return and reflects the risk of the asset relative to the acquired business. These discount rates generally ranged from 12.0% to 14.5% for our 2015 acquisitions for which valuations were performed in 2016. The fair value of non-compete agreements was established using the profit differential method, which is an income approach based on estimated financial projections developed by management for the acquired company using market participant assumptions and various non-compete scenarios.

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Expiration lists, non-compete agreements and trade names related to our acquisitions are amortized using the straight-line method over their estimated useful lives (three to fifteen years for expiration lists, three to five years for non-compete agreements and three to five years for trade names), while goodwill is not subject to amortization. We use the straight-line method to amortize these intangible assets because the pattern of their economic benefits cannot be reasonably determined with any certainty. We review all of our intangible assets for impairment periodically (at least annually) and whenever events or changes in business circumstances indicate that the carrying value of the assets may not be recoverable. In reviewing intangible assets, if the fair value were less than the carrying amount of the respective (or underlying) asset, an indicator of impairment would exist and further analysis would be required to determine whether or not a loss would need to be charged against current period earnings as a component of amortization expense.

Of the $34.2 million of expiration lists and $1.6 million of non-compete agreements related to our acquisitions made during the three-month period ended March 31, 2016, $9.8 million and $0.1 million, respectively, is not expected to be deductible for income tax purposes. Accordingly, we recorded a deferred tax liability of $3.8 million, and a corresponding amount of goodwill, in the three-month period ended March 31, 2016 related to nondeductible amortizable intangible assets.

Our consolidated financial statements for the three-month period ended March 31, 2016 include the operations of the acquired entities from their respective acquisition dates. The following is a summary of the unaudited pro forma historical results, as if these entities had been acquired at January 1, 2015 (in millions, except per share data):

The unaudited pro forma results above have been prepared for comparative purposes only and do not purport to be indicative of the results of operations which actually would have resulted had these acquisitions occurred at January 1, 2015, nor are they necessarily indicative of future operating results. Annualized revenues of entities acquired during the three-month period ended March 31, 2016 totaled approximately $30.0 million. For the three-month period ended March 31, 2016, total revenues and net earnings recorded in our unaudited consolidated statement of earnings related to our acquisitions made during the three-month period ended March 31, 2016 in the aggregate, were $2.2 million and $0.2 million, respectively.

4. Other Current Assets

Major classes of other current assets consist of the following (in millions):

The premium finance loans represent short-term loans which we make to many of our brokerage related clients and other non-brokerage clients to finance their premiums paid to insurance carriers. These premium finance loans are primarily generated by three Australian and New Zealand premium finance subsidiaries. Financing receivables are carried at amortized cost. Given that these receivables are collateralized, carry a fairly rapid delinquency period of only seven days post payment date, and that contractually the underlying insurance policies will be cancelled within one month of the payment due date in normal course, there historically has been a minimal risk of not receiving payment and therefore we do not maintain any significant allowance for losses against this balance.

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5. Intangible Assets

The carrying amount of goodwill at March 31, 2016 and December 31, 2015 allocated by domestic and foreign operations is as follows (in millions):

The changes in the carrying amount of goodwill for the three-month period ended March 31, 2016 are as follows (in millions):

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Major classes of amortizable intangible assets at March 31, 2016 and December 31, 2015 consist of the following (in millions):