What Is MMI (Maximum Medical Improvement) in Minnesota Workers' Comp?

Maximum medical improvement (MMI) is a medical date, not a job status. Under Minn. Stat. § 176.011, subd. 13a, it is the date after which no further significant recovery from the work injury can reasonably be anticipated, based on reasonable medical probability, regardless of subjective complaints of pain.

You can still hurt. You can still have restrictions. MMI means the doctor does not expect significant further improvement.

Why the date matters

Minn. Stat. § 176.101, subd. 1(j) ends temporary total disability (TTD) 90 days after you reach MMI. The 90 days start on the earlier of:

1. the date you receive a written medical report saying you are at MMI, or
2. the date the employer or insurer serves that report on you and your attorney, if you have one.

Once TTD stops under that rule, it generally cannot restart unless you return to work and later become medically unable to continue because of the injury.

The 90-day rule is not the only TTD limit. For injuries on or after October 1, 2008, TTD also ceases at 130 paid weeks under subd. 1(k). Whichever limit hits first ends the weekly total-disability check. Details are in how long workers' comp lasts.

What MMI does not end

Medical treatment. Reasonably required care to cure or relieve the injury can continue. An MMI stamp is not a discharge from the clinic.

TPD. If you are working and earning less because of the injury, temporary partial disability does not stop 90 days after MMI. That is why light duty often becomes the conversation when an MMI report lands.

PPD. Permanency is usually rated at or after MMI. Use the PPD calculator and the PPD schedule by body part. Accepting a PPD check does not lock you into that rating.

Where the MMI report usually comes from

Insurers often get MMI from an independent medical examination. A treating doctor can place you at MMI too. Either way, the clock is about the written report and service, not a comment in a chart that never reached you.

If the report also says you can work without restrictions, expect a NOID. Treat the packet as a deadline document.

Disputing MMI

MMI is an opinion. A treating doctor's later note that you are not at MMI, or that you became medically unable to continue working, is how that fight is usually framed. The statute also says a later worsening does not, by itself, erase an MMI date already determined, with a narrow exception when you become medically unable to continue working.

If a 90-day letter arrives while you are still off work, get the report, the service date, and your restrictions in one pile. Run the TTD calculator so you know what weekly money is about to stop.