There's no single national body that licenses MMA fighters in the United States, the way there isn't one for boxing either. Instead, each state (or tribal nation) runs its own athletic commission, and a fighter has to get licensed by whichever commission has authority over the building the event is in — every single time, even if they fought three weeks ago in a different state. Getting licensed means clearing medical tests, submitting a verified fight record, and sometimes a same-day physical, and any piece of that can go wrong close enough to fight night to pull a fighter off the card entirely.
Why there's no one body to call
Boxing set the template decades ago: the Muhammad Ali Boxing Reform Act, a federal law passed in 2000, left regulation with individual state commissions rather than creating a national boxing authority. MMA grew up under the same structure. When a state legalizes the sport, it typically does so by having its existing athletic commission — often the same one that already handled boxing — take on MMA as well.
Some gaps exist. Alaska has no athletic commission at all, and a handful of other states don't regulate combat sports, which usually just means events there run without a state body overseeing them. Dozens of Native American tribes also run their own athletic commissions on tribal land, independent of the surrounding state, which is why some events are held on tribal property.
Who the ABC is, and what it actually does
The Association of Boxing Commissions and Combative Sports (ABC) is the coordinating body that ties all of this together — but it's not a regulator itself. It's a nonprofit made up of delegates from the state, provincial, and tribal commissions, and it has no legal authority to license anyone or overrule a commission's decision.
What the ABC does do is set shared standards. In 2009 it adopted the Unified Rules of Mixed Martial Arts, the rulebook most U.S. commissions now use so that scoring, fouls, and weight classes don't vary wildly from state to state. It also administers a National MMA ID Card, a credential a fighter applies for once that commissions can check at weigh-ins, and it publishes a running comparison of what each commission requires medically — useful precisely because the requirements aren't identical everywhere.
What a fighter actually has to submit
To get licensed, a fighter applies directly to the commission running the event — not to the ABC and not to the promotion. The paperwork typically includes identification, a verified record of prior professional or amateur fights, and the results of a pre-fight medical exam.
The medical package varies by state but tends to include the same core pieces: bloodwork screening for HIV, hepatitis B, and hepatitis C; a dilated eye exam; and a physical exam, usually required within the past year. Many commissions also require brain imaging — an MRI or CT scan — particularly for fighters with longer careers or a recent knockout loss, along with an EKG to check heart function. New York, for instance, requires a brain MRI within three years and most bloodwork within the past year; Massachusetts asks for a brain scan within five years. On top of the paperwork, some commissions also run a same-day physical at weigh-ins before clearing a fighter to compete that weekend.
A commission physician who isn't satisfied with any of this can deny the license outright, regardless of whether the fighter feels fine or the fight is already sold as part of the card.
Why this gets harder outside the U.S.
International events don't have a U.S.-style commission waiting to take over, so the arrangement depends entirely on the host country. Some countries have an established body that licenses fighters directly. Others — the UK is a clear example — have no statutory regulator for MMA at all, and events there run on the promotion's own medical and safety protocols rather than a government commission's.
In newer markets, promotions often work alongside a developing local federation rather than a fully independent regulator. In the UAE, for example, a national MMA federation has partnered with the UFC and an international amateur federation to build out local oversight, while the promotion has in practice continued leaning on a U.S. commission's rules for events there. The common thread: every international card still needs someone with authority to sign off on fighters, it just isn't always the same kind of body twice.
Why this causes last-minute problems
Because licensing is tied to a specific commission for a specific event, a fighter can be completely fit to compete and still get blocked by paperwork. A real example: a fighter was denied a license in New York over an irregular finding on his pre-fight MRI, scrubbing him from the card. When he tried to rebook weeks later in a different jurisdiction for a different event, the same unresolved imaging issue got him denied again, and he was pulled from that card too.
Mandatory rest periods cause the same problem on a tighter clock. A commission that orders a post-fight medical suspension — a required recovery window, covered in more detail in the ringside doctor's role — won't license that fighter again until the suspension clears, no matter what date a short-notice opportunity lands on. If the timeline is too tight, the opportunity disappears regardless of how ready the fighter feels.
A card moving jurisdictions mid-planning raises the same risk, because a fighter licensed for one state isn't automatically licensed for another. Every commission change resets the clock on paperwork, and if medical results, background checks, or a physical can't be completed before fight week, the commission simply won't clear the fighter in time — which is one of the recurring reasons bouts fall apart in the final days, alongside the injuries and visa issues covered in why fights fall apart in fight week.
The takeaway
Licensing is a per-event, per-jurisdiction process with no shortcut: a fighter cleared last month in one state still has to clear a new commission's paperwork and medicals before the next fight, wherever it happens to land. When a bout gets scratched close to fight night without an injury being announced, a licensing holdup — a medical flag, an unresolved suspension, or a commission change — is a reasonable first guess, and checking the current card is the fastest way to see how the promotion adjusted around it.