SUMMARY OF CRITICAL ACCOUNTING ESTIMATES Claims and Claim Expense Reserves General Description We believe the most significant accounting judgment made by management is our estimate of claims and claim expense reserves. Claims and claim expense reserves represent estimates, including actuarial and statistical projections at a given point in time, of the ultimate settlement and administration costs for unpaid claims and claim expenses arising from the insurance and reinsurance contracts we sell. We establish our claims and claim expense reserves by taking case reserves, adding estimates for IBNR and, if deemed necessary, adding costs for additional case reserves which represent our estimates for claims related to specific contracts which we believe may not be adequately estimated by the client as of that date, or adequately covered in the application of IBNR. Our reserving committee, which includes members of our senior management, reviews, discusses, and assesses the reasonableness and adequacy of the reserving estimates included in our audited financial statements. In accordance with FASB ASC Topic Business Combinations , we allocated the total consideration paid for TMR among acquired assets and assumed liabilities based on their fair values. These assets and liabilities include TMR’s claims and claim expense reserves, which totaled $2.4 billion at March 22, 2019, and consisted of $783.3 million and $1.6 billion included in our Property and Casualty and Specialty segments, respectively. The following table summarizes our claims and claim expense reserves by segment , allocated between case reserves, additional case reserves and IBNR: At December 31, 2021 Case Reserves Additional Case Reserves IBNR Total (in thousands) Property $ 1,555,210 $ 1,996,760 $ 2,825,718 $ 6,377,688 Casualty and Specialty 1,784,334 128,065 5,004,543 6,916,942 Total $ 3,339,544 $ 2,124,825 $ 7,830,261 $ 13,294,630 At December 31, 2020 (in thousands) Property $ 1,127,909 $ 1,617,003 $ 1,627,541 $ 4,372,453 Casualty and Specialty 1,651,150 133,843 4,223,692 6,008,685 Total $ 2,779,059 $ 1,750,846 $ 5,851,233 $ 10,381,138 59