This article examines in detail the specific financial, accounting, and operational changes triggered by the implementation of the IFRS 17 standard. The authors analyze key innovations such as the amortization of acquisition expenses, the introduction of a risk adjustment, the accounting for the time value of money in reserve measurement, and the immediate recognition of losses for onerous contracts. The main liability measurement models are considered: the General Measurement Model (GMM), the Premium Allocation Approach (PAA), and the Variable Fee Approach. Separate attention is paid to the reclassification of expenses and reinsurance transactions. The practical part of the article highlights the main operational challenges faced by Russian insurers: a large-scale change in the chart of accounts, problems with data and its retrospective collection, import substitution difficulties, and the need to maintain dual tax accounting systems. The conclusion is drawn about a significant increase in the complexity of accounting processes and the long-term nature of standard implementation projects.