With its Uniform Plumbing Code, Uniform Mechanical Code, Uniform Solar Energy, Hydronic and Geothermal Code and Uniform Swimming Pool, Spa and Hot Tub Code designated as American National Standards, IAPMO is proud to utilize an open consensus process accredited by the American National Standards Institute (ANSI) in its code development practice.

IAPMO gathers the largest assembly of plumbing and mechanical experts in the world at its annual education and business conference, where anyone — members and non-members alike — can have a voice and a vote on proposed changes to the code.

The purpose of the IAPMO code development process is to ensure the continued development and maintenance of the Uniform Codes with the following goals in the forefront:

  • Effectiveness in preserving the public health, safety, and welfare.
  • The timely evaluation and recognition of technological developments pertaining to construction regulations.
  • A consensus process, which provides for the open discussion of proposals by all parties who wish to participate.

IAPMO urges its members and other interested parties to get involved in the code development process to ensure that these goals are maintained. Installers, plumbing and mechanical officials, the construction industry, engineers, and manufacturers all benefit from a cooperative effort in developing codes.

Click on the following covers to go directly to the individual document development page

Uniform Plumbing Code (UPC)

Uniform Plumbing Code (UPC)

Uniform Mechanical Code (UMC)

Uniform Mechanical Code (UMC)

Uniform Solar, Hydronics and Geothermal Code

Uniform Solar, Hydronics and
Geothermal Code (USHGC)

Uniform Solar, Hydronics and Geothermal Code (USHGC)

Uniform Swimming Pool, Spa
and Hot Tub Code (USPSHTC)

Water Efficiency and Sanitation Standard (We-Stand)

National Standard Plumbing Code (NSPC)
National Standard Plumbing Code (NSPC)

State-Codes based
on Uniform Codes

Sample legislation to adopt
a IAPMO code


The Standards Council will meet on November 14, 2019 to discuss appeals submitted to the 2021 UPC and UMC. Click here to view appeals submitted and the schedule of Appeals..



In accordance with the IAPMO Governing Committee Projects, proposed TIA’s UPC TIA 002-18, UPC TIA 003-18, UMC TIA 006-18, and UMC TIA 007-18, which have been submitted for processing pursuant to Section 5-1 of the Regulations, will be automatically docketed as an appeal on the agenda of the IAPMO Standards Council. Any party may advocate their position before the Council. Please note that parties wishing to address the Council may do so via teleconference or in person. Parties wishing to address the Council shall notify the Council Secretary, Ms. Gaby Davis at, no later than 48 hours prior to the Council meeting. Although not required, individuals wishing to advocate a position are encouraged, to the extent practicable, to file written submission in general conformance with Sections 1-6.3 and 1-6.4 of the Regulations in advance of the meeting at which action will be considered. The proposed TIA’s will be on the council agenda scheduled for Thursday, November 14, 2019. When an automatically docketed appeal has not been pursued by any party, the Council will not consider the matter as an appeal.



Code Errata, Addendums, Tentative Interim Amendments & Formal Interpretations Available Here

Press Releases

2019-10-25 IAPMO Makes Three Tentative Interim Amendments (TIA) Available for Public Comment

2019-10-25 IAPMO Seeks UMC Legionella Task Group Members

2019-10-21 IAPMO Makes New Tentative Interim Amendment (TIA) Available for Public Comment

2019-10-10 IAPMO Solicits Public Comments for 2021 Uniform Solar, Hydronics and Geothermal, Swimming Pool, Spa and Hot Tub Codes

2019-09-09 Report on Proposals (ROP) Toward Development of 2021 USHGC, USPSHTC Now Available for Online Download

2019-09-06 New Jersey Adopts 2018 National Standard Plumbing Code

2019-08-21 Report on Comments Toward Development of 2021 UPC and UMC Now Available for Online Download

2019-08-13 IAPMO Seeks USPSHTC Slip-Resistance Task Group Members

2019-08-13 IAPMO Seeks USHGC Hydronics Task Group Members

2019-07-02 2019 California Plumbing Code, California Mechanical Code Now Available

2019-06-24 IAPMO Advances Development of 2021 Solar, Hydronics & Geothermal Code and Swimming Pool, Spa & Hot Tub Code During Technical Committee Meetings

2019-06-19 St. Louis County Adopts UPC, Provisions of Two Other Uniform Codes

2019-05-20 IAPMO Code Change Monographs Now Available for the USHGC and USPSHTC

2019-05-15 IAPMO Advances Development of 2021 Uniform Codes During Technical Committee Meetings

2019-03-25 IAPMO Code Change Monographs Now Available

2019-03-19 IAPMO Seeks Technical Correlating Committee Members

2019-03-13 National Standard Plumbing Code Public Hearing Set for July 11, 2019

2019-03-08 IAPMO Seeks Technical Subcommittee Members for Development of National Standards IAPMO Z1115 and IAPMO Z1349

2019-02-07 IAPMO Seeks Technical Subcommittee Members for Development of Z1167 Standard as a U.S National Standard for Solid Waste Containment Interceptors

2018-10-29 IAPMO 2021 Solar Energy, Hydronic and Geothermal & Swimming Pool Code Proposals

2018-10-29 IAPMO 2021 Solar Pool TC

2018-08-31 IAPMO 2021 UPC & UMC Public Comment

2018-08-23 IAPMO UPC & UMC ROP

2018-08-22 IAPMO 2018 USHGC & USPSHTC

2021 UPC & UMC CODE Timeline


2018 Uniform Code Highlights

Not All Model Codes Are Created Equally

Model Codes Bring Simplicity, Order to Plumbing Engineer’s Work

How Stakeholders Can Effectively Participate in the Development of Codes and Standards

Standards and Model Codes: A Working Relationship

Circuit Venting Problem Solved: Methods, Connections and More

Plumbing Vent System in Multi-story Building

Fire and Smoke Dampers – The First Line of Defense

The Formation of PERC and the Drainline Carry Research Project

Working to Keep Building Water Systems Safe and Efficient – The Vital Role of the Plumbing Industry

Plumbing Prevention