This excerpt taken from the CVS 10-K filed Feb 27, 2007.
8 Pension Plans and Other Postretirement Benefits
During 2006, the Company adopted SFAS No. 158, Employers Accounting for Defined Benefit Pension and Other Postretirement Plans-an amendment of FASB Statements No. 87, 88, 106, and 132(R). SFAS No. 158 requires an employer to recognize in its statement of financial position an asset for a plans overfunded status or a liability for a plans underfunded status, measure a plans assets and its obligations that determine its funded status as of the end of the employers fiscal year, and recognize changes in the funded status of a defined benefit postretirement plan in the year in which the changes occur. Those changes will be reported in comprehensive income and in a separate component of stockholders equity.