Permanent Medical Impairment (PMI)

Some workplace injuries leave a permanent loss of function even after appropriate treatment. A permanent medical impairment assessment measures that lasting loss, so WCB can determine whether you’re entitled to a permanent impairment benefit (PIB).  This page explains what PMI is, how it’s assessed, how a PMI rating is determined, and what happens after.

What permanent medical impairment is

A PMI is a measurable, lasting reduction in a worker’s function caused by a workplace injury. It might be reduced range of motion in a joint, loss of strength, loss of sensation, loss of ability to carry out the tasks of daily living, or another lasting effect. The nature and extent of a permanent impairment can vary from person to person.

Two things are important about how WCB defines PMI:

• Permanent — the impairment continues even after treatment has done what it can. WCB assesses PMI only after a worker reaches maximum medical recovery (MMR) — the point where further medical improvement isn’t expected.
• Measurable — the impairment can be assessed against standardized criteria. Standardized criteria are used so assessments are consistent across workers, injuries, and assessors.

A PMI rating is expressed as a percentage — a permanent impairment% (PI%). This percentage is used to calculate a worker’s Permanent Impairment Benefit (PIB).

When PMI is assessed

Your WCB case worker will decide if you should be assessed for a PMI.  This may happen when  your injury has reached maximum medical recovery (MMR). MMR is the point where an injury has stabilized and further medical treatment is not expected to improve your recovery.

MMR doesn’t mean you are back to 100%, or that you no longer need support. It means the medical picture has settled enough that any lasting impact can be measured.

How PMI is assessed

Your case worker will make arrangements for you to have a PMI exam.  The exam is performed by a certified PMI Assessor. A Certified PMI Assessor is a doctor trained in determining whether a workplace injury has caused a permanent impairment. They review the medical reports on file and meet with you. The PMI Assessor uses the American Medical Association (AMA) Guides to the Evaluation of Permanent Impairment to measure the PMI and assign a PI%. The AMA Guides are a standardized methodology used by independent medical examiners across North America, including all Canadian workers’ compensation boards.

The AMA Guides give detailed criteria for measuring different kinds of impairment — for joints, the spine, the nervous system, organ systems, vision, hearing, and psychological conditions, among others.

Using a standardized methodology means that two workers with similar injuries should receive similar ratings, regardless of which medical advisor performs the assessment. It also means assessments can be compared consistently across time — important when reassessment is being considered.

What to expect at a PMI assessment Exam

The PMI Assessor’s role is specifically to assess permanent impairment; they don’t make treatment recommendations, comment on return to work, or revisit your original diagnosis.

What happens at the assessment

• The Assessor reviews your claim history and asks questions about your injury and recovery.
• The exam is designed not to be strenuous. The doctor will avoid discomfort as much as possible, whether physical or psychological.
• If you have a physical injury, you’ll have a physical exam and discussion focused on the injury, using tests of things like range of motion, strength, and loss of sensation.
• If you have a psychological injury, the doctor will ask you questions about your current state. You won’t have to describe what caused your injury, go over traumatic events, or recount specific things that happened in the past. Your diagnosis will not be reviewed or questioned.
• Most assessments take 20 to 60 minutes, depending on the injury and the information needed.

Things the Assessor will do:

• Ask questions about your recovery
• Perform tests related to a physical injury, such as taking measurements for movement and strength
• Complete a permanent impairment report
• Determine a PI%

Things they won’t do:

• Send you for medical tests or treatment
• Make recommendations about your ability to work or not work
• Ask you to talk about past traumatic events
• Review your prior medical or psychological diagnosis and make recommendations about it
• Give you information about claim decisions, benefit amounts, timelines and next steps. Your case worker can help with these questions.

Before your appointment

• For physical injuries, wear or bring loose-fitting clothing. Shorts are recommended for lower-body or back assessments; a tank top or t-shirt for upper-body, shoulder, or neck assessments.
• Bring your medications list and any recent medical reports related to the injury.
• Tell us if you need accommodations, such as mobility assistance or an interpreter.
• A chaperone can be present if requested by you or by WCB.
• A family member or support person may attend if both you and the medical advisor agree.

Travel, time away from work, and expenses

• Travel and, in some cases, overnight accommodation may be covered when WCB decides they’re necessary for your assessment.
• Contact your case worker before you book to confirm what’s covered and any limits.
• Keep all receipts. WCB can only reimburse approved costs.
• Submit your expenses through WCB Online with your claim number and appointment details.
• If you miss work to attend, ask your employer to confirm your lost wages. Wages are reimbursed at the same rate used for your temporary earnings-replacement benefit (75% or 85% net earnings).

Learn more about covered expenses.

After the assessment: Permanent Impairment Benefit (PIB)

Your results become part of your claim file. Your case worker will talk to you about them, and you'll receive a written decision letter explaining the outcome of your PMI assessment.

When the assessment determines that you have a PMI and a PI% rating is assigned, you may be eligible for a financial benefit called PIB. Here's what happens next:

• Your case worker will review your eligibility for a Permanent Impairment Benefit (PIB) and determine how your rating relates to any other long-term benefit.
• Your case worker will explain how your benefit is paid — as a monthly payment or a lump sum — based on WCB policy and legislation.
• Your case worker will contact you to walk through the outcome and any decisions in your file.

For details on how PIB and other long-term payments are calculated, see How long-term benefit payments are calculated.

Reassessment of PMI

If your condition changes after your initial PMI assessment — meaning the workplace injury results in a different or greater measurable loss of function than what was previously assessed — you may be eligible for reassessment.

Reassessment is for changes directly related to your original workplace injury. New unrelated medical issues, or worsening from causes unrelated to the workplace injury, such as the general effects of aging, are not what reassessment covers.

How reassessment works

• Reassessments are typically only considered at least 16 months after the most recent assessment.
• New medical reports from your doctor are needed.  These reports will include medical evidence that describes how your condition has changed since the last assessment. 
• If WCB determines a reassessment is needed, you will be scheduled for a reassessment exam.
• The result is a new PI% — which can be higher or lower than the previous one, depending on what’s changed.

Appealing a PMI or PIB decision

Any decision about PMI or PIB can be appealed within 90 days of receiving the written decision.  

Workers can find out more about appeals here.  

Employers can find out more about appeals here.

Questions about your assessment or rating?

• For appointment details, results, or how your rating affects benefits, contact your case worker.
• For accessibility or accommodation requests for your assessment, tell your case worker when scheduling.

Learn more about WCB’s PMI policy in the WCB Policy Manual at wcb.ns.ca/policy-manual.