Glossary

Maximum medical improvement (MMI)

The point in a work injury when the condition has stabilized and further recovery is not expected, so permanent impairment can be measured and rated.

Also called: MMI, medical stability, maximum medical recovery, permanent and stationary

Maximum medical improvement is the date a physician decides an injured worker has recovered as much as treatment is expected to achieve. It does not mean healed or pain-free. It means the condition has plateaued, even if ongoing care continues to maintain it. California uses the term "permanent and stationary" for a similar milestone.

MMI is a hinge in a workers' comp claim. Temporary benefits, temporary total disability and temporary partial, usually end at or near it. The doctor then rates any permanent impairment, often under a state-specified edition of the AMA Guides to the Evaluation of Permanent Impairment, and that rating drives permanent partial disability benefits or settlement value. For the employer, MMI also changes the return-to-work question: restrictions that were expected to lift are now permanent, so temporary light duty gives way to permanent accommodation or a separation decision, with ADA duties attached.

Disputes are common. A carrier may think the worker has plateaued while the treating doctor does not, or the reverse, and an independent medical examination often settles it. Declaring MMI too early can cut off benefits before recovery is complete, and the worker can contest it. The date's effect differs by state, so the state's workers' comp agency is the authority on timing and appeals.

Last reviewed October 10, 2026

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Related terms

Temporary total disability Workers' comp wage-loss benefit paid while an injured worker cannot work at all but is expected to recover, commonly about two-thirds of pre-injury pay. Permanent partial disability A workers' comp benefit for a lasting impairment that limits but does not end a worker's ability to work, set by an impairment rating or state schedule. Independent medical examination (IME) A one-time exam of an injured worker by a physician who is not treating them, used to assess diagnosis, cause, treatment needs, impairment and ability to work. Light duty Temporary, modified work offered to an injured employee whose doctor has set restrictions, so the person stays on the job while recovering from a work injury. Return-to-work program An employer program that brings injured workers back to modified or transitional duty once a doctor clears them, to shorten claims and keep them connected.

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