Note 11. BUSINESS COMBINATIONS Our acquisition strategy focuses on businesses with a leadership team that is committed to best in class culture, extraordinary client service and cross-serving potential. CBIZ has a long history of acquiring businesses that share common cultural values with us and provide value-added services to the small and midsize business market. The valuation of any business is a subjective process and includes industry, geography, profit margins, expected cash flows, client retention, nature of recurring or non-recurring project-based work, growth rate assumptions and competitive market conditions. During the six months ended June 30, 2020, we completed the following acquisitions:  Effective February 1, 2020, we acquired substantially all the assets of Alliance Insurance Services, Inc. (Alliance), a provider of insurance and advisory services based in Washington, DC. Operating results will be reported in the Benefits and Insurance Services practice group.  Effective February 1, 2020, we acquired substantially all the assets of Pension Dynamics Company, LLC (PD), a full-service retirement and benefits plan advisor based in Pleasant Hill, California. Operating results will be reported in the Benefits and Insurance Services practice group.  Effective February 1, 2020, we acquired substantially all the assets of Sunshine Systems (Sunshine), a payroll solutions provider based in Massachusetts. Operating results will be reported in the Benefits and Insurance Services practice group. Aggregate consideration for these acquisitions consisted of approximately $9.4 million in cash, $0.9 million in our common stock and $4.8 million in contingent consideration. Under the terms of the acquisition agreements, a portion of the purchase price is contingent on future performance of the business acquired. The maximum potential undiscounted amount of all future payments that we could be required to make under the contingent arrangements is $6.2 million. As of June 30, 2020, the aggregated fair value of contingent consideration related to these acquisitions was $4.7 million, of which $2.0 million was recorded in Contingent purchase price liability  current and $2.7 million was recorded in Contingent purchase price liability  non-current in the accompanying Consolidated Balance Sheets at June 30, 2020. Refer to Note 7, Fair Value Measurements, for additional information regarding contingent purchase price liability fair value and fair value adjustments. Annualized revenue from the acquired businesses is estimated to be approximately $6.1 million. Pro forma results of operations for these acquisitions have not been presented because the effects of the acquisitions were not significant to our Income from continuing operations before income taxes. During the first six months of 2019, we completed one acquisition, acquiring substantially all of the assets of Wenner Group, LLC (Wenner), located in Denver, Colorado effective January 1, 2019. Wenner is a full service accounting, tax, compliance and financial consulting firm. Operating results are reported in the Financial Services practice group. Consideration for this acquisition consisted of approximately $1.3 million in cash consideration and $1.8 million in contingent consideration. Under the terms of the acquisition agreement, a portion of the purchase price is contingent on future performance of the business acquired. The maximum potential undiscounted amount of all future payments that we could be required to make under the contingent arrangements is $1.8 million, of which $0.6 million was recorded in Contingent purchase price liability  current and $1.2 million was recorded in Contingent purchase price liability  non-current in the accompanying Consolidated Balance Sheets at June 30, 2019. Annualized revenue attributable to Wenner is estimated to be approximately $2.4 million. Pro forma results of operations for this acquisition has not been presented because the effects of the acquisition was not significant to our Income from continuing operations before income taxes. The following table summarizes the amounts of identifiable assets acquired, liabilities assumed and aggregate purchase price for the acquisitions for the six months ended June 30, 2020 and 2019 (in thousands): Six Months Ended June 30, 2020 2019 Cash and cash equivalents $ 125 $  Accounts receivable, net 871 550 Client funds 1,716  Operating lease right of use asset, net 224  Identifiable intangible assets 3,629 654 Other assets 53 5 Operating lease liability - current (66 )  Other current liabilities (779 ) (288 ) Client fund obligations (1,716 )  Operating lease liability - noncurrent (158 )  Total identifiable net assets $ 3,899 $ 921 Goodwill 11,158 2,165 Aggregate purchase price $ 15,057 $ 3,086 The goodwill of $11.2 million and $2.2 million arising from the acquisitions in the first half of 2020 and 2019, respectively, primarily results from expected future earnings and cash flows from the existing management team, as well as the synergies created by the integration of the new business within our organization, including cross-selling opportunities expected with our Financial Services practice group and the Benefits and Insurance Services practice group, to help strengthen our existing service offerings and expand our market position. All of the goodwill is deductible for income tax purposes. Acquisitions of client lists - During the six months ended June 30, 2020, we purchased two client lists in the Benefits and Insurance Services practice group and one client list in the Financial Services practice group for total consideration of $0.6 million, of which $0.3 million is contingent. During the six months ended June 30, 2019, we did not purchase any client lists. Change in Contingent Purchase Price Liability for Previous Acquisitions - During the first half of 2020 and 2019, the fair value of the contingent purchase price liability related to prior acquisitions decreased by $0.2 million and by $0.2 million, respectively. These changes in fair value are attributable to subsequent measurement adjustments based on projected future results of the acquired businesses, net present value adjustments and changes in stock price. These adjustments are included in Other income (expense), net in the accompanying Consolidated Statements of Comprehensive Income. Contingent Payments for Previous Business Acquisitions and Client Lists - We paid $5.9 million in cash and issued approximately 0.1 million shares of our common stock during the six months ended June 30, 2020 for previous acquisitions. For the same period in 2019, we paid $11.3 million in cash and issued approximately 0.1 million shares of our common stock for previous acquisitions. For both the first half of 2020 and 2019, we paid approximately $0.3 million in cash for previous client list purchases.