Uniform Plumbing Code

The Uniform Plumbing Code (UPC) is a model code authored by the International Association of Plumbing and Mechanical Officials (IAPMO), an organization founded in 1926. It establishes minimum standards for plumbing systems across residential, commercial, and industrial installations, addressing fixtures, water supply and distribution, drainage, venting, water heaters, and water efficiency. The UPC is produced using IAPMO's American National Standards Institute (ANSI)-accredited open consensus development process and is republished on a three-year cycle, with editions including 2018, 2021, 2024, and 2027. It is adopted as the governing plumbing code by numerous U.S. states and municipalities, including jurisdictions such as Los Angeles, Houston, Seattle, and Portland.