Receivables Related to Legal Proceedings” (contained in “Legal Proceedings” in Note 13) for additional information about such estimates.

 

Pension and Postretirement Obligations:

 

3M has various company-sponsored retirement plans covering substantially all U.S. employees and many employees outside the United States. The primary U.S. defined-benefit pension plan was closed to new participants effective January 1, 2009. The Company accounts for its defined benefit pension and postretirement health care and life insurance benefit plans in accordance with Accounting Standard Codification (ASC) 715, Compensation — Retirement Benefits, in measuring plan assets and benefit obligations and in determining the amount of net periodic benefit cost. ASC 715 requires employers to recognize the underfunded or overfunded status of a defined benefit pension or postretirement plan as an asset or liability in its statement of financial position and recognize changes in the funded status in the year in which the changes occur through accumulated other comprehensive income, which is a component of stockholders’ equity. While the company believes the valuation methods used to determine the fair value of plan assets are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date.

 

Pension benefits associated with these plans are generally based primarily on each participant’s years of service, compensation, and age at retirement or termination. Two critical assumptions, the discount rate and the expected return on plan assets, are important elements of expense and liability measurement. See Note 10 for additional discussion of actuarial assumptions used in determining pension and postretirement health care liabilities and expenses.

 

The Company determines the discount rate used to measure plan liabilities as of the December 31 measurement date for its pension and postretirement benefit plans. The discount rate reflects the current rate at which the associated liabilities could be effectively settled at the end of the year. The Company sets its rate to reflect the yield of a portfolio of high quality, fixed-income debt instruments that would produce cash flows sufficient in timing and amount to settle projected future benefits. Using this methodology, the Company determined a discount rate of 4.10% for the primary U.S. qualified pension plan and 4.07% for U.S. postretirement plans to be appropriate as of December 31, 2014, which represents a decrease from the 4.98% and 4.83% rates, respectively, used as of December 31, 2013. The weighted average discount rate for international pension plans as of December 31, 2014 was 3.11%, a decrease from the 4.02% rate used as of December 31, 2013.

 

A significant element in determining the Company’s pension expense in accordance with ASC 715 is the expected return on plan assets, which is based on historical results for similar allocations among asset classes. For the primary U.S. qualified pension plan, the expected long-term rate of