An annual income tax deduction allowing taxpayers to recover the cost of business or income-producing property over the [useful life](/glossary/useful-life/) of the property. It is not an immediate deduction of the cost in one year. *See* [Pub. 946, How to Depreciate Property (2020)](https://www.irs.gov/pub/irs-prior/p946--2020.pdf), IRS. *C.f.* [section 179 deduction](/glossary/section-179-deduction/)