Maximum Medical Improvement and Permanent and Stationary: How a QME Decides the Date

Short answer: maximum medical improvement (MMI) and permanent and stationary (P&S) are the same thing in California workers' compensation. The rating schedule defines permanent and stationary as "the point in time when the employee has reached maximal medical improvement (MMI), meaning his or her condition is well stabilized and unlikely to change substantially in the next year with or without medical treatment." MMI is the AMA Guides term, P&S is the California statute-and-regulation term, and a medical-legal report should use both. The date matters because it ends temporary disability, starts permanent disability, triggers the employer's return-to-work offer, and fixes the moment at which impairment is rated. It is also one of the most frequently unexplained opinions in QME reports.

Perry J. Carpenter, DC, QME's report writing course treats P&S/MMI as a single section of the report, and Session 10 (video) walks through how to define the concept for the reader and then apply it to the case. His Session 2 example of a conclusory opinion is a P&S date with nothing after it. This piece is about how to avoid writing that sentence.

What maximum medical improvement means

The AMA Guides, Fifth Edition, define MMI at page 2 as a date from which further recovery or deterioration is not anticipated, although over time there may be some expected change. The Guides add, in Chapter 2, that an impairment should not be considered permanent until the clinical findings show the condition is static and well stabilized, and that this is often twelve months after injury or onset.

California adopted that definition and gave it the one-year horizon. Two sources say the same thing in nearly the same words. The 2005 Permanent Disability Rating Schedule, Section 1: "Permanent and stationary is defined as the point in time when the employee has reached maximal medical improvement (MMI), meaning his or her condition is well stabilized and unlikely to change substantially in the next year with or without medical treatment." Title 8, section 10152 of the regulations: "A disability is considered permanent when the employee has reached maximal medical improvement, meaning his or her condition is well stabilized, and unlikely to change substantially in the next year with or without medical treatment."

The definition turns on three phrases.

Well stabilized. The condition has plateaued. Not cured, not necessarily painless. The findings on exam and the reported function are no longer moving in either direction across visits.

Unlikely to change substantially in the next year. This is the test. The evaluator looks forward twelve months and asks whether the condition will be materially different. Small fluctuations are expected and do not defeat P&S. A pending surgery that is likely to change the outcome does.

With or without medical treatment. Ongoing treatment does not prevent P&S. A worker on a stable medication regimen, in periodic physical therapy, or with an injection every few months can be permanent and stationary. What matters is whether treatment is expected to change the condition substantially, not whether treatment continues.

Permanent and stationary versus MMI

There is no substantive difference. The confusion comes from history. California used "permanent and stationary" for decades before it adopted the AMA Guides for injuries on or after January 1, 2005. The Guides use MMI. The Physician's Guide and 8 CCR 10682 still ask for a P&S opinion; the Guides' report format asks for an MMI date. Dr. Carpenter's hybrid report template resolves it with a single heading, "P&S / MMI status," so the reader who searches the report for either term finds the section.

One practical distinction survives. P&S is a status that applies to the injury as a whole for benefit purposes. MMI can be assessed body part by body part. A worker with a shoulder and a knee can be MMI for the shoulder and still recovering from knee surgery. The report should say so, and should say that the injury as a whole is not yet permanent and stationary, because temporary disability and the permanent disability rating both turn on the whole injury.

How a QME determines the MMI date

The evaluator has three sources: the records, the history, and the examination. The opinion should rest on all three and say which facts came from which.

From the records, the evaluator looks for the plateau. Treating physician notes that show range of motion, strength, and pain scores holding steady across several visits. A surgeon's release. A physical therapy discharge summary that reports goals met or progress stalled. The completion of the treatment the medical treatment utilization schedule supports for the diagnosis. The absence of any pending request for authorization that would change the picture.

From the history, the evaluator asks the worker whether the condition has changed in the last several months and whether any treatment is planned. A worker who reports being the same since the spring is describing a plateau. A worker who is scheduled for a fusion next month is not at MMI, no matter how stable the exam looks today.

From the examination, the evaluator compares current findings to the most recent findings in the records. Consistent findings support stability. Findings that are markedly better or worse than the last note need an explanation before the date can be set.

The date itself is then a judgment, and the report has to say why that date. Common anchors, each of which is defensible when the reasoning is written out:

The date of the evaluation, when the exam confirms a plateau that the records show has been in place for some time.
The date of a surgeon's release or a therapy discharge that marks the end of active treatment.
The date of the last treating note that documents the plateau, where the worker has had no treatment since.
A date roughly one year after surgery, where the Guides' typical recovery period fits the procedure and the records show no further change.

Any of these can be right. None of them is right without the sentence that follows: "My reasons for this conclusion include," and then the records, the history, and the exam findings that support it. The substantial medical evidence standard applies to the P&S date the same as to every other opinion in the report.

When the worker is not at MMI

A QME who finds the worker not permanent and stationary has not failed to answer the question. Not P&S is an answer, and often the correct one. The report should then say three things: what treatment is expected to change the condition, roughly when MMI is anticipated, and what the worker's temporary work status is in the meantime.

The parties will usually bring the worker back once treatment is complete. Under the fee schedule, a follow-up evaluation by the same physician within eighteen months of the comprehensive evaluation bills as ML-202 at $1,316.25, which includes review of 200 pages of new records. If the follow-up falls outside eighteen months, it is a new comprehensive evaluation.

The refused surgery problem

The hardest MMI call is the worker who has a surgical recommendation and does not want the surgery. Nothing in the definition requires a worker to undergo an operation. The accepted approach is to find the worker permanent and stationary as they are, rate the impairment on the current findings, and describe the surgery as future medical care, with the note that if the worker later elects the procedure, the status and the rating may change and a re-evaluation would be appropriate.

What the evaluator should not do is defer the opinion indefinitely because surgery might happen. That leaves the worker on temporary disability with no end and the parties with no rating. The one-year test is explicit: with or without treatment. A worker who has declined treatment is, on the current course, not going to change substantially in the next year.

How long it takes to reach maximum medical improvement

There is no fixed period. The Guides say twelve months is common, and for a surgical case that is a reasonable expectation. A soft tissue strain with no surgery can be P&S in a few months. A multi-level fusion with complications can take two years or more.

Two clocks run in the background. Temporary disability for most injuries is capped at 104 weeks of payments within five years of the date of injury under Labor Code 4656, so a worker can run out of temporary disability before reaching MMI. And the parties themselves have an interest in the date: the applicant because permanent disability advances do not begin until P&S, the defendant because temporary disability stops. The evaluator's job is to ignore both clocks and answer the medical question.

What changes once permanent and stationary is declared

The P&S finding is the hinge of the case, which is why it draws so much attention.

Temporary disability ends. Temporary disability compensates for wage loss during recovery. Once the condition is not going to improve, there is nothing left to recover from, and the benefit stops.

Permanent disability begins. The permanent disability rating is calculated as of the P&S date, using the whole person impairment the evaluator assigns for each body part. Permanent disability payments start when temporary disability ends.

The return-to-work clock starts. For injuries on or after January 1, 2013, Labor Code 4658.7 gives the employer 60 days from receipt of the first report finding the worker permanent and stationary with permanent partial disability to offer regular, modified, or alternative work lasting at least twelve months. If no offer is made, the worker gets a supplemental job displacement voucher. The report that starts the clock can be from the treating physician, an AME, or a QME, and it must be accompanied by the return-to-work form, which is why the work restrictions section of a P&S report has consequences beyond the rating.

The rating goes to the Disability Evaluation Unit. The DEU rates the impairment in the P&S report. What that process looks like, and how the case resolves from there, is covered in what happens after a QME report.

Future medical care is defined. A P&S report has to say what treatment is reasonably required going forward, because the award or settlement will be built around it. That is its own section.

Can a permanent and stationary finding be undone?

Yes, in two ways. If the condition changes substantially after P&S, the worker can petition to reopen for new and further disability under Labor Code 5410, generally within five years of the date of injury. And if a later evaluation finds the worker was never actually at MMI, for example because the pending surgery went forward, the parties can obtain a new report. P&S is a finding about a point in time, not a permanent label on the person.

Writing the section

Dr. Carpenter's practice is to give the reader the definition before applying it, so a claims adjuster or a judge who has never read the rating schedule knows what test is being applied. A workable structure for the section:

State the definition, quoting the schedule or 10152.
State the opinion: P&S, or not P&S, and the date.
List the reasons, with the specific records, history, and exam findings that support the plateau and the date.
If not P&S, state the anticipated treatment, the expected timeframe, and the interim work status.
If multiple body parts are involved, address each one, then the injury as a whole.

The reasons in step three are what make the section defensible, and they come mostly from the records: the sequence of treating notes that shows the plateau, the therapy discharge, the surgical release, the absence of a pending authorization request. In a large production those entries are scattered across hundreds of pages from several providers. Lexamed builds the dated chronology from the full file with a page citation on every entry, so the evaluator can see the treatment course laid out in order and point to the notes that show where it flattened. The date is still the physician's call, made from a treatment course that is already laid out in order.

Frequently asked questions

What is maximum medical improvement? The point at which an injured worker's condition is well stabilized and unlikely to change substantially in the next year, with or without medical treatment. It does not mean the worker is cured or pain-free. It means the condition has plateaued.

Is permanent and stationary the same as MMI? Yes. Permanent and stationary is the California term and MMI is the AMA Guides term. The 2005 rating schedule defines permanent and stationary as the point at which the worker has reached maximal medical improvement.

How is maximum medical improvement determined? By comparing the treatment records, the worker's history, and the current examination to see whether the condition has plateaued and whether any planned treatment is expected to change it substantially within a year. The evaluator then selects a date and explains the reasons for it.

How long does it take to reach maximum medical improvement? There is no fixed period. The AMA Guides note that twelve months after injury or surgery is common. Minor injuries can reach MMI in months; complex surgical cases can take two years or more.

What happens after maximum medical improvement in workers' comp? Temporary disability ends, permanent disability begins, the impairment is rated, the employer's 60-day window to offer regular, modified, or alternative work under Labor Code 4658.7 opens, and the report defines the future medical care the award or settlement will cover.

Can you be permanent and stationary while still receiving treatment? Yes. The definition is explicit that the condition is unlikely to change substantially with or without treatment. Ongoing medication, periodic therapy, or injections do not prevent a P&S finding if they are not expected to change the condition.

What if the worker refuses recommended surgery? The evaluator can find the worker permanent and stationary on the current findings, rate the impairment as it is, and describe the surgery as future medical care, noting that the status and rating may change if the worker later elects the procedure.

Can a permanent and stationary finding be changed later? Yes. If the condition changes substantially, the worker can petition to reopen for new and further disability under Labor Code 5410, generally within five years of the date of injury, and a later evaluation can revise the finding.