How Impairment Ratings Work in Utah Workers' Comp

If MMI is the most important date in your case, your impairment rating is the most important number. A single percentage decides how big your PPD check will be — and a 5% difference can mean $20,000.

The short version

• An impairment rating is a percentage assigned by a doctor at MMI.
• Utah uses the AMA Guides to Permanent Impairment (6th edition, by reference).
• Rating × 312 weeks × your TTD weekly rate = your PPD total.
• Insurance doctors trend low. Independent doctors trend higher. Both can be challenged.

How a rating is assigned

At MMI, your doctor examines you and measures objective findings: range of motion, strength, neurological function, X-ray or MRI evidence of permanent damage. They then look up your condition in the AMA Guides and assign a percentage.

Two types of ratings:

1. Whole Person Impairment (WPI) — used for back, neck, organ, brain, and most injuries. The percentage applies to your whole body.
2. Body Part Impairment — used for hands, fingers, arms, legs. The percentage applies to that body part and is then converted to WPI.

Utah uses WPI for the PPD calculation. So if a doctor gives you "30% upper extremity," that converts to roughly 18% WPI before the math hits.

The PPD math, in plain English

PPD total = Impairment % × 312 weeks × TTD weekly rate

Worker earning $1,200/week, 12% WPI rating:

• TTD weekly: $1,200 × 0.6667 = $800
• PPD weeks: 12% × 312 = 37.4 weeks
• PPD total: 37.4 × $800 = $29,920

Same worker, 17% WPI: PPD jumps to $42,398. That 5% difference = $12,478.

How to challenge a low rating

1. Get a second opinion from a different specialist — orthopedist, neurologist, or pain management depending on your injury type. Pay for it yourself if needed; $500 spent can recover $20,000 in higher PPD.
2. Request an IME from the Labor Commission if the rating dispute is significant. The Commission can order a neutral IME paid by the insurance carrier.
3. Hire an attorney if disputes get formal. Utah caps WC attorney fees at 25%, paid only if you win — no upfront cost.

Common mistakes around impairment ratings

Mistake 1: Accepting the first rating without review

Insurance adjusters move fast after MMI: "Here's your rating, here's our offer." Slow down. Ask for the doctor's written report. Read the AMA section they cited. Compare against second-opinion estimates.

Mistake 2: Confusing impairment with disability

Impairment is a medical measurement. Disability is functional impact (can you work? at what kind of job?). A 10% impairment could mean total disability for a roofer or no disability for a desk worker. Utah pays PPD based on impairment %, not real-world impact — but disability arguments still matter for vocational rehabilitation and settlement negotiations.

Mistake 3: Not getting a written report

Verbal ratings don't count. Demand a written report citing the AMA Guides page and table used. Without it, you can't effectively appeal.

Run the math for your case

Already have your rating? Plug it into the CVR Quick Calculator — it does the PPD multiplication using current 2026 Utah rates. Don't have a rating yet? Save the calculator URL; you'll want it once your doctor declares MMI.