Why fewer than 1% of denied claims are ever appealed

Every year, U.S. health insurers deny something north of 90 million claims. Some estimates put the real number much higher — KFF's analysis of just the ACA marketplace suggested 17% of in-network claims get denied, and that's only one slice of the system. Add Medicare, Medicaid, employer plans, and Medicare Advantage and the total balloons.

What's striking isn't the denial rate. It's the appeal rate.

Federal data and KFF's own analysis put the formal appeal rate at well under 1%. In some years, on some carriers, it dips below 0.2%. Out of every thousand denials, fewer than two are challenged.

Insurers don't talk about this number, but they design around it. Denial letters use language that sounds final — 'denied,' 'not medically necessary,' 'does not meet criteria.' They omit the appeal instructions, or bury them on page four. They cite reason codes that look impenetrable to anyone outside the industry.

The result is a system that works on cognitive overload. The denial arrives at exactly the moment when you're least able to fight it — sick, scared, exhausted, or watching a parent in pain. A whole department of people who do nothing but write denials goes up against a private citizen who has 30 days, no template, and no idea where to start.

And so 99% of the time, nothing happens. The denial stands. The bill goes to collections, or the prescription goes unfilled, or the surgery gets rescheduled into next year, or never. The carrier wins by default.

Here's what's also true: when denials are appealed, they reverse. KFF's analysis found that internal appeals reverse at roughly 41%. External reviews (the next level up) reverse at higher rates in many states.

The math is brutal in both directions. A <1% appeal rate is a system designed to lose your appeal for you. The reversal rate when someone actually appeals is dramatically higher than that — and in our pilot caseload it has tracked above the industry baseline.

If your denial letter is sitting on the kitchen counter, you're not alone — you're in the 99%. We exist to move you out of that group.