AARP Foundation Tax-Aide will offer its free in-person income tax preparation service for low-to-moderate income taxpayers, with special attention given to people age 50 and older at four sites in Butler County.

Membership in AARP is not required. All sites require an appointment in advance and are obtained only by calling 211 after Monday, Jan. 16. Taxpayers should bring a photo ID along with their prior year (2021) tax returns.

The sites are:

— 10 a.m. to 3 p.m. Mondays from Feb. 6 through April 17, but closed for the Feb. 20 Presidents’ Day holiday, with an extra date of Feb. 22 at Cranberry Public Library, 2525 Rochester Road, Cranberry Township

— 10 a.m. to 3 p.m. Tuesdays from Feb. 7 through April 11 at Mars Area Public Library, 107 Grand Ave., Mars

— 9:15 to 11:45 a.m. and 12:30 to 3 p.m. Tuesdays from Feb. 7 through April 11 at the Tanglewood Center, 10 Austin Ave., Butler Township

— 9:15 to 11:45 a.m. and 12:30 to 3 p.m. Thursdays from Feb. 2 through April 13, Trinity Lutheran Church, 120 Sunset Drive, Butler.

Federal and Pennsylvania state taxes are due April 18 this year.