How to Calculate Your Iowa Impairment Rating Payout

To calculate an Iowa impairment rating payout, you multiply three numbers: the statutory weeks assigned to the injured body part (or 500 weeks if the injury is to your back, neck, head, or trunk), your impairment rating percentage, and your weekly benefit rate. The weekly rate is 80% of your spendable earnings, capped at $2,162 for injuries occurring between July 1, 2025, and June 30, 2026.¹² The math is straightforward for arms, legs, hands, and feet. For back, neck, head, and trunk injuries, the percentage you plug in is often not your medical rating at all, and that is where most of the misunderstanding happens.

The Two Numbers You Need First

Every calculation starts with an impairment rating and a weekly earnings figure. The rating is a percentage assigned by a physician using the AMA Guides to the Evaluation of Permanent Impairment, done once you reach maximum medical improvement — the point where your condition has stabilized as much as it’s going to.³ The rating usually comes from the employer’s doctor, though you have the right to seek your own.

Your pre-injury gross earnings come from pay stubs or payroll records for the weeks before the accident. Iowa’s definition of gross earnings covers recurring pay before deductions and excludes irregular bonuses, overtime, penalty pay, and expense reimbursements.⁴ A small error here compounds across dozens or hundreds of weeks of benefits, so the number is worth checking carefully.

Turning Earnings Into Your Weekly Benefit Rate

Your weekly PPD benefit equals 80% of your spendable weekly earnings. Spendable earnings are what remains after payroll taxes are subtracted from gross weekly wages. Payroll taxes for this purpose include federal income tax withholding, Iowa state income tax withholding, and Social Security contributions, all calculated using the withholding tables in effect on July 1 before your injury.⁴ The withholding assumes the maximum exemptions you’re actually entitled to based on dependents, age, and blindness.

The result is bounded. The annual maximum is set at 200% of Iowa’s statewide average weekly wage, and the Workers’ Compensation Division publishes new rate tables every July.¹ For injuries occurring between July 1, 2025, and June 30, 2026, the PPD maximum is $2,162 per week and the minimum is $411 per week.² The rate that applies to your claim is locked to the date of injury, not the date you file or settle.

Scheduled Injuries: Arms, Legs, and Everything With a Fixed Week Count

Iowa assigns a fixed number of compensation weeks to specific body parts. For these “scheduled members,” multiply the statutory weeks by your impairment percentage, then multiply by your weekly benefit rate.⁵ The calculation ignores how the injury affects your job or earning power. If the schedule says 190 weeks and your rating is 10%, you get 19 weeks of benefits whether or not the injury forces you to change careers.

The full schedule under Iowa Code 85.34(2):³

Shoulder: 400 weeks
Arm: 250 weeks
Hand: 190 weeks
Leg: 220 weeks
Foot: 150 weeks
Eye: 140 weeks (200 weeks if the other eye was already lost)
Hearing in one ear: 50 weeks
Hearing in both ears: 175 weeks
Thumb: 60 weeks
Index finger: 35 weeks
Second finger: 30 weeks
Third finger: 25 weeks
Little finger: 20 weeks
Great toe: 40 weeks
Other toes: 15 weeks each

Losing a single phalange of a finger or toe counts as losing half that digit. Losing more than one phalange counts as losing the entire digit.³

A Worked Example

You injure your hand and the doctor assigns a 10% impairment rating. Your weekly benefit rate is $1,500. The payout: 190 weeks × 10% = 19 weeks. Then 19 weeks × $1,500 = $28,500 in total PPD benefits, paid out in weekly installments unless the parties agree to a lump sum.

Unscheduled Injuries: Back, Neck, Head, and Trunk

Injuries to the back, neck, head, and trunk are not on the schedule. They fall under Iowa Code 85.34(2)(v), which uses a baseline of 500 weeks, but the percentage you apply is not simply your medical impairment rating.³ The statute ties your benefit to the reduction in your earning capacity, a figure called “industrial disability.”

The Workers’ Compensation Commissioner determines industrial disability by weighing your impairment rating alongside your age, education, work history, physical restrictions, rehabilitation potential, and how much earning power you’ve actually lost.⁵ A 15% impairment rating can translate into a 30% or 40% industrial disability when the injury effectively locks a worker out of the only kind of work they’ve done for twenty years.

One exception cuts in the other direction. If you return to work with the same employer at the same or higher pay, compensation is based only on your functional impairment percentage, not the broader earning capacity analysis.³ If that employer later terminates you, the statute lets you reopen the case and seek a new determination based on lost earning capacity.

A Worked Example

A warehouse worker with a back injury receives a 15% impairment rating. She is 52, has no college degree, and has spent her career in physical labor. After weighing those factors, the commissioner finds her industrial disability is 25%. The payout: 500 weeks × 25% = 125 weeks. At a $1,800 weekly rate, that is $225,000. Had she returned to the same job at the same pay, the award would instead rest on the 15% rating alone: 500 × 15% = 75 weeks × $1,800 = $135,000.

Face and Head Disfigurement Works Differently

Permanent scarring or disfigurement of the face or head has its own provision under Iowa Code 85.34(2)(u). There is no fixed week count tied to a rating. The commissioner sets the number of compensable weeks based on the severity of the disfigurement, up to 150 weeks, and only if the disfigurement impairs your future usefulness and earnings in the occupation you held at the time of injury.³ If this is your situation, the formula above does not apply.

When the Calculation Becomes Real

PPD benefits do not begin the moment you’re hurt. They start when a medical provider indicates you’ve reached maximum medical improvement and the extent of your permanent impairment can be measured using the AMA Guides.³ Before that point, you may receive temporary total disability or healing-period benefits instead. The move to PPD payments marks the point where your condition is treated as permanent and the numbers above actually come into play.

If the Rating Looks Too Low

If the employer’s doctor assigns a rating you think understates your condition, Iowa Code 85.39 gives you the right to an independent medical examination at the employer’s expense.⁶ You apply to the Workers’ Compensation Commissioner and deliver a copy of the application to your employer and its insurance carrier. The physician you choose can request the full injury history from the employer’s doctor.

The employer only owes reimbursement for a reasonable exam fee if the injury is ultimately found to be compensable. What counts as “reasonable” is measured against the typical fee for an impairment rating in the area where the exam takes place.⁶ Because the rating is the lever that moves the entire calculation, getting it right is usually the single most valuable step a worker can take before accepting a payout figure.

1
Iowa Legislature. Iowa Code 85.37 – Compensation Schedule
2
Department of Inspections, Appeals, & Licensing. Rate Information
3
Iowa Legislature. Iowa Code 85.34 – Permanent Disabilities
4
Iowa Legislature. Iowa Code 85.61 – Definitions
5
Department of Inspections, Appeals, & Licensing. Benefits
6
Iowa Legislature. Iowa Code 85.39 – Examination of Injured Employees