What is Max Medical Improvement?

Clayton T. Hasbrook

Written by Clayton T. Hasbrook. Last modified on February 20, 2024

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Maximum medical improvementMaximum Medical Improvement, or MMI for short, is a simple yet important concept in every personal injury claim. It refers to the point in your medical treatment beyond which you are not expected to get any better from further medical care. This is not to imply that your medical treatment is finished. You will still require ongoing treatment (e.g., medications, physical therapy, or assistive devices), but this treatment is intended to maintain your current level of health and functioning. It’s a bad idea to settle a personal injury case until the patient fully recovers or reaches MMI. A few examples should make this concept easier to understand.

Examples of MMI

Example 1: Steve is involved in a car accident and suffers a herniated disc in his lower back. This herniation causes not only pain but also causes Steve’s legs to go numb occasionally. Steve has surgery on his back, which removes the occasional numb feeling, but he still has pain. Six months after Steve’s surgery, Steve’s doctor concluded that another surgery would not relieve Steve’s pain and that Steve was as good as he would get. Steve will require medications for his back pain for the foreseeable future. He will have stretching exercises to perform and is restricted from certain activities that could re-injure or aggravate his back. At this six-month post-surgery point, Steve is at MMI. Steve is not as healthy as he was before the accident, and he never will be, but his doctor has concluded that Steve has achieved the maximum level of recovery that medicine can provide.

Example 2: Ann slipped and fell in a grocery store and tore her rotator cuff when she put her arm down to break her fall. Ann had surgery to repair her rotator cuff, but six months after the surgery, Ann still had a great deal of pain in her shoulder and did not have a good range of motion in that arm. Ann underwent physical therapy and takes her medications as directed, but she is still not improving. It turns out that scar tissue formed around her surgery site (a common complication), and a second surgery to remove the scar tissue is recommended. Ann is not yet at MMI, as her doctor still believes that her pain level and range of motion will improve from the second surgery (and Ann has no objection to having another surgery).

Example 3: Joe strained his lower back when he slipped on spilled grease on the floor at a fast food restaurant. His lower back pain improved over eight months of treatment but did not disappear entirely. His doctor does not expect that Joe will ever be pain-free from this injury, and Joe will require over-the-counter pain medication, a heating pad, and occasional muscle relaxers to treat his back pain from now on. At the point Joe’s pain level stopped improving and leveled off, Joe was at MMI.

Why does MMI matter?

MMI is important to a personal injury case because it allows the plaintiff’s lawyer to predict your future damages — medical costs, lost wages, and pain and suffering. Until you have reached MMI, a fair settlement value or jury verdict will be near-impossible to determine. For example, the woman in “Example 2” may have thought she would only require one surgery to repair her torn rotator cuff. Had she settled her case before reaching MMI, she would not have accounted for the additional medical costs, pain, and lost work time from her second surgery.

Often, when you reach MMI, your doctor will sometimes assign you a “permanent impairment rating,” which is a number given as a percentage, representing the reduced functioning of your body. There are two types of impairment ratings: one for the injured body part and one for your whole body. For example, you could have a 15% impairment rating for your right arm and a 6% full-body impairment. What this means is that your arm is functioning at 15% less than it was before the accident, translating into your entire body functioning at 6% less (I just pulled these numbers out of a hat — they are not from the official guidelines, most frequently the AMA Guides to the Evaluation of Permanent Impairment, your doctor will use). If you have injuries to more than one body part, each will be assigned an impairment rating, and the guidelines will show how they are added together to reach a whole body impairment number. A permanent impairment rating allows lawyers and insurers to compare the values between different injuries, but it is not an exact science. An impairment rating will not be assigned until you reach MMI.

Who Decides When I’ve Reached MMI?

Your doctor, not your lawyer, will decide when you reach MMI. Remember, it’s a maximum medical improvement, not a legal improvement.

Does Being at MMI Mean That My Medical Condition Won’t Worsen?

No. Often, people at MMI are expected to get worse as time passes. The most common example is someone developing arthritis in an injured joint. However, being at MMI makes it easier for your doctor to predict how your condition will worsen over time so that you can recover from this expected downturn in your health.

When will I reach MMI?

Each person’s medical treatment (and case) differs, but most doctors will not consider placing you at MMI until at least six months after your injury. This varies wildly, as someone young may recover significantly faster. It could be much longer, sometimes years in cases with multiple complications. This can be frustrating for plaintiffs, who want to be compensated quickly after an accident. However, waiting until you are at MMI or through with your medical treatment is the best way to ensure that you are fully compensated for your injuries.


This page has been written, edited, and reviewed by a team of legal writers following our comprehensive editorial guidelines. This page was approved by Founding Partner, Clayton T. Hasbrook who has years of legal experience as a personal injury lawyer. Our last modified date shows when this page was last reviewed.