The definition
The AMA Guides Newsletter's jurisdictional review describes MMI as a well-stabilized state unlikely to change substantially in the next year, with or without treatment. New York (12 NYCRR 324.1), Texas (28 TAC 130.1), and Washington's handbook each restate this core with local refinements.
Why the date matters
In Texas, an impairment rating is invalid if it is based on a date that is not the MMI date — the rating and the date must both appear on the Report of Medical Evaluation. In New York, SLU is evaluated at MMI. In California, permanent disability is rated at MMI under the PDRS.
State differences
- New York: no MMI before 6 months in non-surgery/non-fracture cases (12 NYCRR 324.1)
- Texas: designated doctor certifies MMI and rating; presumptive weight
- Colorado: DIME resolves MMI disputes within 30 days of the dispute
- Washington: handbook defines MMI and report content (WAC 296-23-382)
When examiners disagree
The dispute-resolution path is jurisdictional: DIME in Colorado, designated doctor in Texas, panel QME in California. The disagreement usually comes down to whether further treatment could substantially change the condition — the exact question the MMI definition answers.
Practice points
Document the basis for the MMI date (findings, imaging, treatment plateau). Distinguish 'no lasting improvement' from 'no further reasonable treatment.' Keep the date consistent across the report, forms, and rating.
