National Standard Plumbing Code

The National Standard Plumbing Code™ (NSPC)

The PHCC has maintained what is now known as the National Standard Plumbing Code™ (NSPC) since first publishing a standard plumbing code in 1933. By signing an agreement to move the NSPC under the International Association of Plumbing and Mechanical Officials (IAPMO) umbrella, IAPMO and the PHCC ensure the code can progress for years to come.

Designed to ensure the proper installation of plumbing systems, the NSPC provides local and state governments, code administrative bodies, and industry with a modern code to protect public health and safety.

2018 National Standard Plumbing Code Illustrated provides the latest information about common materials, fixtures, devices and equipment systems used or installed in plumbing systems. It is compatible with codes used nationwide and follows the numerical sequence of ANSI A.40.8. The code contains many revisions that have been included to promote sustainable plumbing practice. Appendix G is intended to promote sustainable plumbing practice and has been updated with revised excerpts from the IAPMO Green Plumbing and Mechanical Code Supplement. Used in conjunction with PHCC’s Plumbing Apprentice Training Program, the guide’s illustrations and supplementary notes make it an indispensable training tool.

To keep the code current and viable and with input from all interested parties, the NSPC Committee — comprised of licensed contractors, engineers, and inspectors — reviews the code annually and updates it on a three-year cycle.

Code Development

The National Standard Plumbing Code (NSPC) Committee was held the 2019 NSPC Public Hearing on July 11, 2019, at Bally's in Atlantic City, New Jersey. The NSPC proposed changes approved at the July hearing will appear in the 2021 National Standard Plumbing Code–Illustrated. The NSPC Committee reviews the code annually and updates it on a three-year cycle.

Download the NSPC Public Hearing Final Committee Action Matrix
Click to download the 2021 NSPC Matrix of Changes and Proposed Code Changes
Download the 2021 NSPC Proposed Code Changes Addendum


Purchase 2018 National Standard Plumbing Code

   If you are ordering from the following states, please contact your state bookstore to order: 
   Maryland: Phone (410) 461-5977 or email   
   New Jersey:
 Phone (800) 652-7422 or email

Online Editions

   Read 2018 National Standard Plumbing Code
   Read 2015 National Standard Plumbing Code 


   Download Errata to 2018 2nd Printing
   Download Errata to 2018 1st Printing
   Download Errata to 2015 1st Printing

Have a Question

   Email us at

NSPC Interpretation Inquiries

   Informal: Doug Kirk, Technical Services Supervisor,
   Formal: Dan Cole, NSPC Secretary,