External Review: After Your Appeal Fails

When an insurer denies your prior authorization or claim and your internal appeal is also denied, you are not out of options. Federal law — and state laws in most states — gives you the right to have that decision reviewed by an independent organization that has no financial relationship with your insurer. That review is binding on the insurer: if the external reviewer decides in your favor, the insurer must cover the service or pay the claim.

This guide explains how external review works, when it is available, and how to request it. For the preceding step, see the How to Appeal a Denial guide.

What external review is and why it exists

External review was established as a patient protection under the Affordable Care Act, building on state external review laws that existed in many states before 2010. The goal is to provide an independent check on insurer denial decisions — a review conducted by clinicians and reviewers who are not paid by or affiliated with the insurer.

Before external review existed, an insurer’s internal appeal process was the last word on coverage disputes (outside of litigation). External review created a faster, lower-cost alternative: an independent expert reviews the same clinical question the insurer decided, without the insurer’s financial interest in the outcome.

An Independent Review Organization (IRO) is the entity that conducts the external review. IROs must be accredited, must have no conflict of interest with the insurer or patient, and must assign reviewers who have relevant clinical expertise to evaluate the specific type of denial being reviewed.

When external review is available

External review becomes available when:

1. You have exhausted the internal appeals process — meaning the insurer has issued a final denial of your internal appeal, or
2. Your appeal is deemed exhausted — the insurer violated the required internal appeals procedures, allowing you to bypass the internal process and go directly to external review.

Not every denial is eligible for external review. External review generally applies to denials based on:

• Medical necessity or appropriateness
• Level of care (e.g., inpatient versus outpatient)
• Clinical setting or effectiveness
• Experimental or investigational treatment status

Denials based solely on a service being excluded from your plan’s covered benefits — not a medical necessity question, but a plan design question — are generally not eligible for external review. Those require a different challenge, such as a complaint to the state insurance commissioner.

How to request external review: step by step

1. Receive your final internal appeal denial. The denial letter must state that you have exhausted internal appeals and describe your right to external review.
2. Note the deadline. You generally have four months from the date of the final internal appeal denial to request external review. Do not delay.
3. Submit your external review request to your insurer (not directly to the IRO). The insurer receives the request, selects an accredited IRO, and transmits the case file.
4. Provide any additional documentation. You may submit additional clinical records, physician statements, or published evidence at this stage. The more complete the record, the better.
5. The insurer transmits the file to the IRO — usually within five business days of receiving your request.
6. The IRO reviews the case. The assigned reviewer will examine the clinical records, the insurer’s criteria, your plan documents, and any additional information submitted.
7. Receive the decision. Standard decisions must come within 45 days. Expedited decisions must come within 72 hours.
8. The decision is implemented. If the IRO reverses the insurer’s denial, the insurer must authorize and cover the service or pay the claim.

What the IRO examines

The IRO reviewer — typically a board-certified physician with relevant specialty expertise — evaluates the denial using the same clinical information the insurer had, plus anything you submitted. The review considers:

• Whether the service meets the insurer’s clinical criteria for coverage
• Whether the service meets recognized standards of medical practice
• Whether the insurer applied its criteria correctly and consistently
• In some cases, whether the plan’s coverage criteria are themselves reasonable in light of accepted medical standards

The IRO does not simply repeat the insurer’s analysis — it applies independent clinical judgment to the same facts. Reversals are more common than many patients expect, particularly for denials involving newer treatments, off-label uses with strong clinical evidence, or conditions where clinical guidelines have evolved.

Standard vs. expedited external review

Type	When to use	Decision deadline
Standard external review	Most denials where the situation is not immediately urgent	45 days from request
Expedited external review	When a standard timeline could seriously harm your health, or when you are in the middle of an ongoing treatment	72 hours from request

Request expedited review when your physician documents that waiting 45 days would seriously jeopardize your health or ability to regain maximum function. The request for expedited review should include a letter from your physician explaining the clinical urgency.

The binding nature of the decision

External review decisions are binding on both parties under federal rules. This is what makes external review meaningful as a patient protection:

• If the IRO reverses the insurer’s denial, the insurer must cover the service. It cannot continue to deny based on the same facts.
• If the IRO upholds the insurer’s denial, the insurer’s decision stands. The patient cannot request another external review of the same denial under the same process.

The binding nature of the decision does not affect other legal options — a patient may still file a complaint with their state insurance commissioner or pursue litigation. But within the insurance coverage dispute process, an IRO decision is final.

Documents and terms you’ll see

When preparing for external review and corresponding with the IRO and your insurer, watch for these terms:

• External review — the independent review process; your final internal appeal denial must notify you of this right and provide instructions for requesting it
• Independent Review Organization (IRO) — the accredited entity that conducts the review; your insurer selects the IRO from a list of accredited organizations, but the IRO has no financial relationship with the insurer
• Internal appeal — the prerequisite step; the insurer’s final denial of your internal appeal is what opens the door to external review
• Binding decision — the legal effect of the IRO’s outcome; a reversal compels coverage, and the insurer cannot re-deny the same claim based on the same facts
• Deemed exhaustion — if the insurer failed to follow required internal appeals procedures, your appeal is deemed exhausted and you may request external review without completing the internal process

For a complete picture of the dispute and appeal process, start with the Prior Authorization and Referrals guide and the How to Appeal a Denial guide.