All guides · Denial categories
Denial categories
Strategy by denial type — medical necessity, prior authorization, plan exclusion, out-of-network, and more.
When your insurer says a service wasn't medically necessary, you're being asked to prove a clinical case. The strongest appeals in this category combine a treating-provider letter, peer-reviewed support, and a plan-language anchor.
Writing the medical necessity argumentThe prong-by-prong attack on a medical-necessity denial using the NAIC three-prong definition, plan-language anchoring, and ACA appeal-rights framing.
Insurance appeal letter examples — what works by denial typeHow appeal emphasis shifts across the five core denial categories — what to highlight, what evidence helps, and which CARC codes you are likely to see.
MRI denied by insurance — the full appeal guideHow to use the ACR Appropriateness Criteria, clinical history (symptom duration, exam findings, prior workup), and the plan's medical-necessity language to win an MRI appeal.
Bariatric surgery denied — your appeal optionsA criterion-by-criterion walkthrough of bariatric appeals — BMI thresholds, 6-month supervised programs, co-morbidities, psych eval, sleeve vs. bypass, and plan exclusions.
TMS denied — the appeal blueprint for treatment-resistant depressionThe chart-level documentation that makes TMS appeals win: drug-class diversity, therapeutic doses, adequate trial durations, PHQ-9 thresholds, and FDA/APA citations.
Cigna denial appeals explainedExplains Cigna's centralized appeals unit, Evernorth/Express Scripts/Accredo involvement on pharmacy denials, and how to dismantle a medical-necessity denial by quoting Cigna's own SPD definition.
No Surprises Act: what it covers and what it doesn'tFederal protections for emergency services, OON ancillary at in-network facilities, and air ambulance; the IDR back-end; notice-and-consent waiver risks; ground-ambulance gap; how to invoke the Act in an OON appeal.
InsureDefense is not a law firm, insurer, medical provider, or claims adjuster. We do not provide legal, medical, or insurance advice. We prepare appeal documents based on the information you provide. We do not guarantee approval, payment, coverage, or reimbursement. For urgent medical situations, contact your doctor, insurer, or emergency services directly.