Impairment Income Benefits (IIB)

When IIB starts

Entitlement begins the day after you reach maximum medical improvement, or the day after your temporary benefits expire — whichever happens earlier.

That second trigger matters. A worker who exhausts 104 weeks of temporary benefits without any doctor declaring MMI still moves into the impairment phase. The clock does not wait for the medical opinion.

Once the carrier knows your impairment, it must pay benefits within 14 days.

How much IIB pays

The rate is 75% of your average weekly temporary total disability benefit, capped at the statewide maximum under § 440.12. Payment is biweekly.

If you have returned to work and earn at or above your average weekly wage in a given week, that week’s benefit is reduced by 50%.

Worked example. Your AWW is $900, so your TTD rate is $600 per week. Your IIB rate is 75% of $600, which is $450 per week. If you go back to work earning your full pre-injury wage, that drops to $225 for those weeks.

How many weeks you receive

For accidents on or after October 1, 2003, the number of weeks is tiered — the higher your rating, the more weeks each additional point is worth:

• Each point from 1% through 10% — 2 weeks
• Each point from 11% through 15% — 3 weeks
• Each point from 16% through 20% — 4 weeks
• Each point from 21% and higher — 6 weeks

Continuing the example. A 12% impairment rating produces (10 × 2) + (2 × 3) = 26 weeks. At $450 per week, that is $11,700 total.

A 22% rating produces (10 × 2) + (5 × 3) + (5 × 4) + (2 × 6) = 67 weeks. Tiering means a rating that is only ten points higher is worth roughly two and a half times as much—which is why disputes over a percentage point or two are worth taking seriously.

Benefits continue until the weeks are exhausted or the employee dies.

What IIB does not cover

Impairment income benefits are payable only for ratings of physical impairment.

Where objective medical findings substantiate a permanent psychiatric impairment resulting from the accident, permanent impairment benefits for that psychiatric impairment are limited to 1% permanent impairment. That is the statutory ceiling regardless of how severe the psychiatric condition is.

Where IIB goes wrong

• A rating that is too low. Because weeks are calculated per percentage point and the schedule is tiered, small rating differences produce large benefit differences. This is the single highest value thing to check.
• A zero rating. No rating, no impairment benefit. A zero rating after a genuine permanent injury is worth a second medical opinion.
• Apportionment. Under § 440.15(5), a pre-existing condition is apportioned out based on the anatomical impairment rating attributable to it. Carriers sometimes apportion aggressively on thin evidence.
• Late payment. Benefits are due within 14 days of the carrier’s knowledge of the impairment. Late payment can carry penalties and interest.
• The 50% earnings reduction applied wrongly. The reduction applies only to weeks in which you earn at or above your AWW — not to any week you happen to be working.

What this means for your claim

IIB is arithmetic, which makes it easy to check. You need three numbers: your correctly calculated AWW, your TTD rate, and your impairment rating. From those, the weekly amount and the total number of weeks follow mechanically.

Run the calculation yourself. If the carrier’s total doesn’t match, the discrepancy is almost always in the rating or the AWW—and you can challenge both. Because impairment benefits are also a significant component of settlement value, an error here follows you into any settlement discussion.