Only 5% of denied health claims were ruled 'not medically necessary'
The villain image is an insurer overruling your doctor. The data says that is the rare case. Seven times as many denials came with no stated reason at all.
An analysis of ACA in-network claims puts denial rates between 13% and 35% depending on the insurer. The breakdown beneath that range is the surprise.
Only about 1 in 20 denials cited medical necessity. The rest were administrative: excluded services, missing referrals or prior auth, or a reason the insurer simply never gave.
The thread's twist: 'never specified' is not the same as harmless.
A denial is rarely a doctor being overruled
Randal Olson's analysis, which is now retired and redirected but quoted verbatim in the thread, reports ACA in-network claim denial rates ranging from roughly 13% to 35% depending on insurer. Its sharper claim is about what those denials are. The popular image — an insurer overruling a doctor on whether care is needed — is, the analysis reported, the exception. Only about 5% of denied in-network claims were turned down as not medically necessary. The rest were administrative.
| Denial reason (in-network) | Share |
|---|---|
| Not medically necessary | ~5% |
| Administrative: excluded service, missing referral / prior authorization, or a reason the insurer never specified | the remainder |
| In-network denial rate, range across insurers | ~13%–35% |
The post's framing is that the headline denial numbers reflect messy billing and coding more than care-rationing villainy. The thread accepted the breakdown, then turned the reassuring read inside out. If only 5% cite necessity, the other categories deserve scrutiny too:
"It seems kind of silly to tout the 5% 'not medically necessary' line when 7 times as many were denied for 'a reason the insurer never specified'." — a commenter re-reading the source's own breakdown
Where do administrative denials come from? One former insider pointed at the provider side of the ledger:
"I worked in health tech for a while, and I can tell you the muck around a lot with ICD/CPT codes to maximize billing … a project at an innovation center … leveraged ML to maximize the amount of codes they could bill for" — a former health-tech worker
Another showed that a low denial rate can be an illusion produced by a thin network:
"I was on one of the insurers that denied the fewest claims. However, they also had the fewest doctors … the only podiatrist was 50 miles away … the same ultimate result of denying claims." — a commenter recounting a narrow-network plan
And the cost-exposure that denial rates never capture surfaced from someone with good coverage:
"When I went to an in-network ENT … they were billed $850 … The insurance said they'd pay $550. So I got to pay the rest. And this is gold coverage with an already-met deductible." — the author of Beej's Guides and a CS instructor at Oregon State–Cascades
The reason the 5% figure misleads is structural, and the thread keeps circling it: the experience patients fear — blocked, costly, unexplained care — does not live in the 'medically necessary' column. It lives in the administrative remainder, in the network map, and in the bill that arrives after a claim was technically approved.
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