Every payer denies differently. Here's how to appeal each one.

UnitedHealthcare is the largest commercial payer, and for an independent practice it's also one of the most edit-heavy: automated policy edits, aggressive E/M review, and a two-step reconsideration-then-appeal path run mostly through the UnitedHealthcare Provider Portal.

UnitedHealthcare runs an E/M coding-accuracy program that reviews high-level office and outpatient visits (like 99204/99205 and 99214/99215) and can pay a lower level than you billed based on the diagnosis and reported complexity.

UnitedHealthcare prior-authorization denials mean the required pre-approval wasn't on file, wasn't linked to the claim, or was obtained for the wrong code.

Aetna denials for independent practices are driven heavily by its Clinical Policy Bulletins and precertification requirements, with disputes and appeals running through the Availity provider portal.

Most Aetna medical-necessity denials trace to a Clinical Policy Bulletin — Aetna's published coverage policy for a service.

Cigna denials for independent practices cluster around modifier and E/M policies, medical-necessity coverage positions, and documentation-request edits, with disputes run through the CignaforHCP provider portal.

Cigna has pursued policies that scrutinize modifier 25 — the modifier that lets you bill a significant, separately identifiable E/M on the same day as a minor procedure — including proposals to require records up front or reduce the E/M payment.

Blue Cross Blue Shield isn't one payer — it's a federation of independent local plans (Anthem, Highmark, Horizon, Florida Blue, Regence, and many more), each with its own policies, portal, and appeal rules.

Anthem Blue Cross (part of Elevance Health) operates Blue Cross and Blue Cross Blue Shield plans across more than a dozen states.

Humana's book is heavily Medicare Advantage, so for independent practices its denials mostly follow MA rules — which means the appeal path depends on whether you're contracted or not.

Humana Medicare Advantage denials follow CMS appeal rules layered on top of Humana's own policies.

UMR is UnitedHealthcare's third-party administrator (TPA) for self-funded employer plans.

Meritain Health is Aetna's third-party administrator for self-funded employer plans.

Oscar Health is a technology-first insurer concentrated in the ACA individual marketplace and small-group market.

Health Care Service Corporation (HCSC) is the largest customer-owned health insurer in the country and operates the Blue Cross Blue Shield plans in Illinois, Texas, Oklahoma, New Mexico, and Montana.

Ambetter is Centene's ACA marketplace brand, sold through state-based health plans (Ambetter from Sunshine Health, from Superior HealthPlan, and so on).

Anthem (part of Elevance Health) runs coding-accuracy and E/M review programs that can reduce a high-level office visit (like 99204/99205 or 99214/99215) to a lower level based on the diagnosis and reported complexity.

Beyond its Clinical Policy Bulletins, Aetna applies a layer of automated claim edits — bundling, modifier, frequency, and E/M coding-accuracy rules run through its edit engine — that reduce or deny payment before any human looks at the claim.

EviCore (an Evernorth/Cigna company) is a benefit-management vendor that runs prior authorization for many health plans — Cigna and various commercial and Medicare Advantage plans — across radiology and advanced imaging, cardiology, radiation and medical oncology, musculoskeletal, sleep, lab, and post-acute care.

Carelon Medical Benefits Management (an Elevance Health company, formerly AIM Specialty Health) runs prior authorization for Anthem, many Blue Cross Blue Shield plans, and other payers — covering advanced imaging, cardiology, oncology, radiation oncology, sleep, musculoskeletal, and genetic testing.