Why is the fire code different in every state?

There is no national fire code. Model codes are written by private organisations, principally the International Code Council and NFPA, and they have no legal force anywhere until a state or a local government adopts them. Each jurisdiction chooses which model code to adopt, which edition, and what to amend, and those three choices are made on completely independent schedules.

The gap is much wider than people expect

Two verified examples, both current as of August 2026.

• California runs a triennial cycle. Its 2025 edition of the California Fire Code, Title 24 Part 9, took effect on 1 January 2026 and is built on the 2024 International Fire Code.
• Indiana enforces the 2014 Indiana Fire Code at 675 IAC 22-2.5, effective 1 December 2014, which adopts the 2012 International Fire Code. No newer edition appears in the commission's published rules. See which fire code Indiana uses.

That is a twelve year gap in the underlying model code between two states, and neither is doing anything unusual. Adoption lag of several years is the norm rather than the exception, because adopting a code is a rulemaking process with hearings, comment periods and a legislature or commission that has other business.

What this means when you read anything about fire code

An article citing a section number of the 2024 IFC is describing California. It is not describing Indiana, and it may not describe your state either. The section may have been renumbered, the requirement may have changed, or it may not exist in the edition your inspector is working from.

This is a large part of why articles about how often a hood must be cleaned disagree with each other so confidently. Many of them are accurate about some edition, somewhere.

The four layers, and every one of them can add

1. The model code, written by the ICC or NFPA, with no legal force by itself.
2. State adoption with amendments. The state picks an edition and modifies it, so the adopted text is not identical to the model text.
3. Local amendments. Cities and counties may add to the state code. These are genuinely local and are not collected anywhere centrally.
4. The authority having jurisdiction, normally your local fire marshal, who interprets and enforces all of it for your specific building.

A referenced standard such as NFPA 96 comes in through this stack rather than applying on its own, which is why the answer to almost every question here ends with your AHJ rather than with a section number.

How to find out what applies to you

Call your local fire prevention bureau and ask two questions. Which edition are you enforcing, and are there local amendments affecting commercial kitchen exhaust. It takes about five minutes and it is the only authoritative answer available.

Ask the same question of your kitchen exhaust cleaner. A competent local contractor works to the adopted edition every day and usually knows the local amendments better than any published summary.

The part that does not vary

Whatever edition applies, you will be asked to produce dated evidence that the work was done. The interval is local and contested. The requirement to have a record is not.

Adoption details verified August 2026 against the Indiana Fire Prevention and Building Safety Commission's published rules and the California Building Standards Commission's code cycle. Both change. Confirm the current adoption with your authority having jurisdiction before relying on either.