Where and how is International Mechanical Code (IMC) adopted across jurisdictions?

Currently, 45 states have adopted the International Mechanical Code (IMC) (IMC) as part of their building standards. You can see the full list of jurisdictions including specific editions and amendments in the table and interactive map.

While the ICC publishes new editions of the IMC every 3 years (e.g., 2018, 2021, 2024), actual state adoption varies. Most states are currently transitioning between the 2018 and 2021 editions. Use the map to see specifically which edition your state uses.

Yes, very few states adopt the IMC exactly "as is." Most states implement significant amendments to address local climate, seismic, or legislative requirements. These are categorized as "State Amended" or "State Edition" in our database.

The IMC is published by the ICC. It is part of a comprehensive suite of codes designed to provide consistent safety standards across the built environment.

Compliance depends on the state and local jurisdiction where your project is located. If the jurisdiction has adopted the IMC (as shown on the map), all new construction and renovations must typically comply with its provisions unless exempt.

"As Is" means the state uses the code exactly as published by ICC. "State Amended" means they use the base code but have added, deleted, or modified specific sections (like snow loads or energy values) to fit local conditions. "State Edition" means they reprint the entire code with their changes included.