External Review: The Binding Second Opinion Insurers Fear

Eligible: denials resting on medical judgment — medical necessity, experimental/investigational determinations, appropriateness of setting or level of care, and rescissions of coverage. Not eligible: pure legal/contractual disputes like clear benefit exclusions or eligibility questions, which route to regulators or courts instead.

You generally must exhaust the internal appeal first, with two exceptions: urgent cases can run expedited external review in parallel, and if the insurer commits serious procedural violations in the internal process, you may be deemed to have exhausted it.

The request window is generally four months from the final internal denial. Your final denial letter must explain how to file — through your state's process, or the federally-administered process where states lack one. Filing is a form plus your record; some states route it through the insurer, who must forward it.

Standard reviews are decided within 45 days; expedited reviews within 72 hours where the standard timeline would seriously jeopardize health. The IRO assigns clinicians in the relevant specialty.

External reviewers decide on the record against current medical evidence — not the insurer's internal policy. Front-load everything: the physician's letter addressing the insurer's criteria, records, guidelines and literature, and your internal appeal correspondence showing what the insurer ignored.

Frame the question clinically: 'the treating physician's judgment, supported by [guideline], is that this care is medically necessary for this presentation; the insurer's denial rests on [criteria] which the record satisfies as follows.' Decisions in your favor are binding — the plan must pay.