{
 "cite": {
  "title": "Why US health insurers deny claims, denial reasons by share of denials",
  "url": "https://denialfacts.com/denial-reasons",
  "publisher": "Axion Labs — Denial Facts",
  "checked": "2026-09-05",
  "dataset": {
   "version": "2026-09-05",
   "fixity": "sha256-70fcef553523e50058a299023fafac57763341dfadc1bbd86b956b6fe1079dd3"
  },
  "source": {
   "name": "CMS Transparency in Coverage Public Use File (PY2026 release, PY2024 claims), data.healthcare.gov",
   "url": "https://data.healthcare.gov/"
  },
  "rule": null,
  "license": "free to quote with the URL",
  "receipt": null
 },
 "attribution": {
  "source": "Denial Facts (https://denialfacts.com) — computed from the CMS Transparency in Coverage Public Use File",
  "upstream": "CMS Transparency in Coverage Public Use File (PY2026 release, PY2024 claims), data.healthcare.gov — US Government public domain",
  "upstream_license": "US Government public domain",
  "facts_checked": "August 3, 2026",
  "license": "Free to use, including commercially, with attribution and a link to https://denialfacts.com",
  "operator": {
   "name": "Axion Labs",
   "email": "hello@getaxionlabs.com"
  },
  "disclaimer": "Federal statistics and a general description of appeal rights created by federal law. Not legal, medical, or insurance advice, and no outcome is guaranteed. Your denial letter and plan documents govern your specific case."
 },
 "count": 9,
 "note": "Query one with /api/answer?reason={slug}. Combine with &insurer= and &state=.",
 "reasons": [
  {
   "slug": "not-medically-necessary",
   "label": "Not medically necessary",
   "claims_denied_nationally": 3968921,
   "share_of_categorized_denials_pct": 4.6,
   "what_it_means": "The insurer says the treatment was not needed for your condition. This is the denial type independent external review is designed for, because it is a clinical judgment made by someone who has never examined you — and your own doctor's letter of medical necessity directly contradicts it.",
   "page": "https://denialfacts.com/denial-reasons/not-medically-necessary",
   "answer": "https://denialfacts.com/api/answer?reason=not-medically-necessary"
  },
  {
   "slug": "out-of-network",
   "label": "Provider out of network",
   "claims_denied_nationally": 8567575,
   "share_of_categorized_denials_pct": 9.8,
   "what_it_means": "The insurer says your provider is outside its network. Federal law under the No Surprises Act restricts balance billing for emergency care and for out-of-network providers at in-network facilities — many of these denials should never have been issued.",
   "page": "https://denialfacts.com/denial-reasons/out-of-network",
   "answer": "https://denialfacts.com/api/answer?reason=out-of-network"
  },
  {
   "slug": "service-excluded",
   "label": "Service excluded from the plan",
   "claims_denied_nationally": 10129111,
   "share_of_categorized_denials_pct": 11.6,
   "what_it_means": "The insurer says your plan does not cover this service at all. Check the exclusion against your actual plan documents (the Evidence of Coverage), not the summary — exclusions are frequently applied too broadly, or to the wrong billing code.",
   "page": "https://denialfacts.com/denial-reasons/service-excluded",
   "answer": "https://denialfacts.com/api/answer?reason=service-excluded"
  },
  {
   "slug": "experimental-investigational",
   "label": "Experimental or investigational",
   "claims_denied_nationally": 101612,
   "share_of_categorized_denials_pct": 0.1,
   "what_it_means": "The insurer says the treatment is unproven. This is a denial type external review is well suited to, because independent reviewers judge it against current clinical evidence rather than the insurer's internal policy.",
   "page": "https://denialfacts.com/denial-reasons/experimental-investigational",
   "answer": "https://denialfacts.com/api/answer?reason=experimental-investigational"
  },
  {
   "slug": "referral-required",
   "label": "Referral required",
   "claims_denied_nationally": 7304650,
   "share_of_categorized_denials_pct": 8.4,
   "what_it_means": "The insurer says you needed a referral first. Often an administrative failure rather than a coverage decision — and retroactive referrals are routinely accepted when requested.",
   "page": "https://denialfacts.com/denial-reasons/referral-required",
   "answer": "https://denialfacts.com/api/answer?reason=referral-required"
  },
  {
   "slug": "benefit-limit-reached",
   "label": "Benefit limit reached",
   "claims_denied_nationally": 3646507,
   "share_of_categorized_denials_pct": 4.2,
   "what_it_means": "The insurer says you have used up a limit on this benefit. Check whether the limit is even lawful: annual and lifetime dollar limits on essential health benefits are prohibited.",
   "page": "https://denialfacts.com/denial-reasons/benefit-limit-reached",
   "answer": "https://denialfacts.com/api/answer?reason=benefit-limit-reached"
  },
  {
   "slug": "member-not-covered",
   "label": "Member not covered",
   "claims_denied_nationally": 5729108,
   "share_of_categorized_denials_pct": 6.6,
   "what_it_means": "The insurer says you were not enrolled when the service happened. Usually an eligibility or data error — the fix is proof of enrollment on the date of service, not a clinical argument.",
   "page": "https://denialfacts.com/denial-reasons/member-not-covered",
   "answer": "https://denialfacts.com/api/answer?reason=member-not-covered"
  },
  {
   "slug": "administrative",
   "label": "Administrative reason",
   "claims_denied_nationally": 19612209,
   "share_of_categorized_denials_pct": 22.5,
   "what_it_means": "A paperwork denial: wrong code, missing information, late filing. The cheapest denial to overturn, because it is about correcting a form, not proving a case.",
   "page": "https://denialfacts.com/denial-reasons/administrative",
   "answer": "https://denialfacts.com/api/answer?reason=administrative"
  },
  {
   "slug": "other",
   "label": "Other reasons",
   "claims_denied_nationally": 28113631,
   "share_of_categorized_denials_pct": 32.3,
   "what_it_means": "Denials the insurer did not place in a named category. Ask in writing for the specific reason and the plan provision it relies on — they must give it to you.",
   "page": "https://denialfacts.com/denial-reasons/other",
   "answer": "https://denialfacts.com/api/answer?reason=other"
  }
 ]
}