Maximum Medical Improvement (MMI) and Impairment Rating (IR) Evaluations

How MMI and IR Evaluations work in a Texas workers' compensation case.


Your Treating Doctor or Referral Doctor may request that you undergo an evaluation called an ‘Impairment Rating’ Examination. Another doctor other than your Treating Doctor can also request this but it must be authorized and approved by your Treating Doctor per TDI-DWC Rule. This examination is typically ordered once a worker reaches Maximum Medical Improvement (MMI) in their workers' comp case, so  it can be determined if their accepted or compensable injury may be issued an Impairment Rating, if the injury is permanent and qualifies for a rating. As stated in Rule 130.1, a doctor who certifies that an employee has reached maximum medical improvement (MMI) shall assign an impairment rating for the current compensable injury using the rating criteria contained in the appropriate edition of the Guides to the Evaluation of Permanent Impairment, published by the American Medical Association (AMA Guides). The impairment rating can only be assigned under Texas approved medical textbook per Section 408.124 of the Texas Labor Code (*)  and the appropriate edition of the AMA Guides to use for certifying examinations conducted on or after October 15, 2001 is the fourth edition of the AMA Guides.

Texas Labor Code (TLC), Section 408.124. IMPAIRMENT RATING GUIDELINES.

(a) An award of an impairment income benefit, whether by the commissioner or a court, must be based on an impairment rating determined using the impairment rating guidelines described by this section.

(b) For determining the existence and degree of an employee's impairment, the division shall use "Guides to the Evaluation of Permanent Impairment," third edition, second printing, dated February 1989, published by the American Medical Association.

(c) Notwithstanding Subsection (b), the commissioner by rule  may adopt the fourth edition of the "Guides to the Evaluation of Permanent Impairment," published by the American Medical Association, or a subsequent edition of those Guides, for determining the existence and degree of an employee's impairment.

In a Texas workers' compensation claim, the Impairment Rating is issued to an employee after it has been determined by a Doctor who is Certified and this means that the Doctor has undergone the state-required training and has passed the required testing. The MMI/IR Certified Doctor evaluation and examination’s findings of their accepted or compensable conditions provide the basis of determining if the conditions have reached maximum medical improvement (MMI) and the numerical impairment rating (IR) dictates the future benefits they may receive.

Maximum Medical Improvement (MMI) has been defined as the earlier of, “(A) the earliest date after which, based on reasonable medical probability, further material recovery from or lasting improvement to an injury can no longer reasonably anticipated; (B) the expiration of 104 weeks from the date on which income benefits begin to accrue; or (C) the date determined as provided by Section 408.104.” Texas Labor Code §401.011(30).

Impairment Rating (IR) is a numerical rating that reflects the permanent deficiency of an accepted or compensable condition that resulted from an accepted injury and represents the entire body, or whole person (WP).

A workers' impairment rating is issued after your accepted or compensable condition(s) have been determined to have reached Maximum Medical Improvement (MMI), which, in simple terms, is the point at which your Treating Doctor basically says, "Your condition(s) have reached a point where it is as good as you're going to get with our without additional treatment." Once the worker’s comp doctor determines that the worker has achieved MMI, the doctor will then issue an Impairment Rating to illustrate how well the recovery went. This impairment rating may indicate to what degree the injury(ies) amy affect future job performance. Or to put it more simply, imagine you are selling a car online and you describe the exterior as an 8 out of 10 and the interior as a 7 out of 10. An impairment rating is just like that but for injured workers. This is dictated by Section 408.123 of the Texas Labor Code. It reads as follows:

After an employee has been certified by a doctor as having reached Maximum Medical Improvement, the certifying doctor shall evaluate the condition of the employee and assign an impairment rating using the impairment rating guidelines described by Section 408.124. If the certification and evaluation are performed by a doctor other than the employee's treating doctor, the certification and evaluation shall be submitted to the treating doctor, and the treating doctor shall indicate agreement or disagreement with the certification and evaluation.”

For most minor injuries, when a person obtains MMI, they have improved to their maximum, and their maximum happens to be a complete recovery. But you can also be injured and obtain MMI (as good as you're going to get) yet you've only got some of your health back. For workers who make a full recovery, yes MMI is the end of the case. However, for workers who never make a full recovery, MMI just means that you're as good as you're going to get. In short, MMI just means that you've gotten as well as can be expected, not that you are completely well and an impairment rating may be assigned,

After reaching MMI and receiving this rating, an injured worker is no longer eligible for the Temporary Income Benefits (TIBs) they should have been receiving. However, once a worker is assigned an Impairment Rating they stand to gain a different kind of workers' compensation income benefits. These are, not surprisingly, called Impairment Income Benefits (IIBs). In addition, you have the right to dispute an impairment rating by having your Treating Doctor request an Alternative Impairment Rating (AIR) and you have 90-days to do so starting on the date you receive the report from the first impairment rating evaluation.