WEYERHAEUSER CO

CRIT ICAL ACCOUNTING ESTIMATES

In the preparation of our financial statements we follow established accounting policies and make estimates that affect both the amounts and timing of the recording of assets, liabilities, revenues and expenses. We base our judgments and estimates on historical experience and assumptions we believe are appropriate and reasonable under current circumstances. Actual results, however, could differ materially from the estimated amounts we have recorded. Some of these estimates require judgments about matters that are inherently uncertain. Accounting policies whose application involve a significant level of estimation uncertainty and may have a material effect on our results of operations or financial condition are considered critical accounting estimates.

DISCOUNT RATES FOR PENSION AND POST-EMPLOYMENT BENEFIT PLANS

Discount rates are used to estimate the net present value of our pension and other post-employment plan obligations. These rates are determined at the measurement date by matching current spot rates of high-quality corporate bonds with maturities similar to the timing of expected cash outflows for benefits. The selection of discount rates requires judgment as well as the involvement of actuarial specialists. These specialists assist with selecting yield curves based on published indices for high-quality corporate bonds and projecting the timing and amount of cash flows associated with our obligations to ultimately support our determination of an appropriate discount rate for each plan.

Our discount rates as of December 31, 2023 are:

Pension expenses for 2024 will be based on the 5.2 percent and 4.7 percent assumed discount rates for the U.S. pension plans and the Canadian pension plans, respectively, and the 5.1 percent and 4.6 percent assumed discount rates for the U.S. and Canadian post-employment benefit plans, respectively.

WEYERHAEUSER COMPANY >2023 ANNUAL REPORT AND FORM 10-K 54

Our discount rates are important in determining the cost of our plans. A 50 basis point decrease in our discount rate would increase expense or reduce a credit by approximately:

Details about our other significant accounting policies are in Note 1: Summary of Significant Accounting Policies.

PROSPECTIVE ACCOUNTING PRONOUNCEMENTS

A summary of prospective accounting pronouncements is in Note 1: Summary of Significant Accounting Policies.