Had Shoulder Surgery on the Job in Iowa? Your Impairment Rating May Be Too Low.

A recent Iowa Supreme Court ruling means thousands of injured workers may have been shortchanged on their workers’ comp benefits — sometimes by tens of thousands of dollars. Here’s how to tell if it happened to you.

If you injured your shoulder at work in Iowa and had surgery to fix it, the size of your workers’ compensation check depends on a single number called your impairment rating. That number, expressed as a percentage, is supposed to capture how much function you’ve permanently lost. Multiply it by the value of your shoulder under Iowa law, and you get your benefits.

The problem? For years, that number has been calculated using a method that the Iowa Supreme Court just said is wrong.

On May 15, 2026, in a case called Koeller v. Cardinal Logistics, the court overturned the way Iowa’s workers’ compensation system has been rating one of the most common parts of shoulder surgery. The fix — depending on your specific case — could be worth a real chunk of money.

This post explains, in plain English, what the ruling means, who it affects, and what you should do if you think your rating was lowballed.

What an Impairment Rating Actually Is

After workplace surgery, a doctor evaluates how much permanent damage your body has suffered. They give you a percentage — for example, “12% impairment of the upper extremity.” That percentage drives almost everything in a workers’ comp claim involving a permanent injury.

In Iowa, a shoulder injury is worth up to 400 weeks of benefits. The percentage of your impairment determines how many of those weeks you actually get paid for. So a small change in the percentage can mean a large change in your check.

What Changed in the Koeller Ruling

The case involved a truck driver named Kevin Koeller who tore his rotator cuff yanking on a stuck truck door. As part of his shoulder surgery, his surgeon performed a distal clavicle excision — a procedure that removes a small piece of the collarbone where it meets the shoulder. It’s one of the most common add-on procedures in shoulder surgery. Many people who’ve had rotator cuff repair had a distal clavicle excision too, often without knowing the name for it.

Here’s where things went sideways for Kevin and likely for many others.

Iowa law requires doctors to use a specific medical reference book — the AMA Guides to the Evaluation of Permanent Impairment — to calculate impairment ratings. The book contains tables with numbers for different injuries. For a distal clavicle excision, the relevant table assigns a 10% impairment.

But for years, the workers’ compensation agency was reducing that 10% number by multiplying it by 25%, bringing it down to just 2.5%. That single adjustment took a chunk out of the rating of nearly every Iowa worker who had this type of surgery as part of their shoulder repair.

The Iowa Supreme Court has now said that adjustment is incorrect. The full 10% applies. No reduction.

Who This Ruling Actually Helps

Let’s be honest about this — not everyone with a low shoulder rating is helped by the Koeller decision. This ruling specifically helps people who meet all of the following:

• You had a work-related shoulder injury in Iowa
• You had shoulder surgery as a result
• Your surgery included a distal clavicle excision (sometimes called a “distal clavicle resection” or “DCE”)
• You received an impairment rating that used the reduction we described above

If all of those fit, your rating — and your benefits — may have been calculated incorrectly.

How to Find Out If You Had a Distal Clavicle Excision

Most patients never remember every detail of their surgery. But your operative report does. Here’s how to check:

• Request your operative report from the hospital or surgery center where you had the procedure. You’re legally entitled to it.
• Look for these terms: “distal clavicle excision,” “distal clavicle resection,” “DCE,” or “Mumford procedure.” Any of these mean you had this procedure as part of your surgery.
• Check your impairment rating report. If your rating mentions the AMA Guides Table 16-27 or Table 16-18, that’s a strong signal the rating may need to be re-examined.

If you don’t have these documents, we can help you get them.

What You Should Do Next

If you think the Koeller ruling might apply to your case, time matters. Some workers’ comp claims have strict deadlines for reopening or appealing a decision. Others may already be past the window for changes. The only way to know is to have someone look at your specific situation.

A few things worth knowing before you call any law firm:

• You don’t have to switch lawyers if you already have one. If you have a workers’ comp attorney and want a second look at how your rating was calculated, that’s a normal request.
• An initial consultation should be free. No reputable workers’ comp firm in Iowa or Nebraska will charge you to ask whether your case is worth reviewing.
• You pay nothing unless we win. That’s how workers’ comp cases work in Iowa — attorney’s fees come out of the recovery, not your pocket.

About Our Firm

Johnson Tabor & Johnson Law is based in Omaha but handles workers’ compensation cases on both sides of the river — including Iowa shoulder claims. Adam Tabor is admitted to practice in both Nebraska and Iowa and has been closely tracking how the Iowa Supreme Court has reshaped this area of law over the past several years. We’ve helped injured workers across the Midwest recover what they’re actually owed, not what an insurance carrier wants to pay.