What Is an External Review — and How to Request One

When your insurer says no for the last time, an independent outsider can overrule them — for free, and their answer sticks.

By the Fight Back editorial team · Banana Bay Press · Updated July 26, 2026

An external review sends your denied health insurance claim to an independent third party — an Independent Review Organization — that is not your insurer. After you finish your internal appeal and get a final denial, you request the review in writing, usually within four months. It is generally free, and the reviewer's decision is binding on your insurer.

What an external review is

An external review is the step that comes after you have appealed to your insurance company and lost. Instead of your health plan deciding your case again, the file goes to an Independent Review Organization (IRO) — a neutral third party with no financial stake in the outcome. Medical experts there look at your denial fresh and decide whether the insurer was right.

The right to an external review comes largely from the Affordable Care Act (ACA), which gives most people in most plans a way to take a denied claim outside the company that denied it. It applies to denials based on medical judgment — for example, a service the plan calls "not medically necessary" or "experimental." If you have already read our overview of how to appeal a denied health insurance claim, external review is the stage that follows your internal appeal.

Why it's powerful (the decision is binding)

Here is the part that surprises people: the external reviewer's decision is binding on your insurer. If the IRO decides in your favor, your health plan is required by law to accept that decision and cover the service or item. The company cannot simply disagree and walk away.

That is what makes external review one of the strongest tools you have. During an internal appeal, the insurer is grading its own homework. During an external review, an outsider grades it — and the outsider's answer wins. It is also generally free to you, so there is little downside to using the right you already have.

When you're eligible

Most people with health coverage can request an external review, but a few conditions usually apply:

• You have finished your internal appeal and received a final denial. In most cases you must complete the plan's internal process first.
• The denial involves medical judgment or a decision that a service is not covered, not medically necessary, experimental, or investigational — or it is a rescission (cancellation) of your coverage.
• Your plan is subject to the external review rules. Most plans are, though a small number of older "grandfathered" plans may not be.

Common denials that reach this stage include imaging, surgeries, mental health care, and prescription drugs. If a medication was turned down, our guide on what to do when insurance denied your medication walks through the internal appeal that comes first.

How to request one, step by step

The exact address, form, and contact details are printed on your final internal denial letter (sometimes called your final adverse determination). Here is the general path:

1. Confirm you have a final internal denial The letter should say your internal appeal is complete and explain your right to an external review.
2. Read the instructions on that letter It tells you where to send your request, whether to use a state or federal process, and the exact deadline.
3. Gather your documents Collect the denial letters, your policy or plan summary, and any records or a note from your doctor supporting the care.
4. Submit a written request in time File your request for external review before the deadline. Keep a copy and proof of the date you sent it.
5. Add a doctor's statement for urgent cases If your health is at serious risk, ask for an expedited review and include your provider's support for the urgency.
6. Wait for the binding decision The IRO reviews your file and issues a decision your insurer must follow.

Standard vs. expedited external review

There are two speeds, and you pick based on how urgent your situation is.

A standard external review is the default. Once the IRO has your request, a decision generally arrives no later than 45 days after the request is received. Some state processes use somewhat different timelines, so treat this as a general figure and check your letter.

An expedited external review is for urgent medical situations — where waiting could seriously jeopardize your health or your ability to regain function. In those cases, a decision is typically made within 72 hours or less, depending on the urgency. For truly urgent care, you may also be able to request an expedited external review at the same time as your internal appeal, rather than waiting for the internal process to finish.

State vs. federal process

Which body handles your review depends on where you live and how your plan is set up. Many states run their own external review programs that meet federal standards; if yours does, your claim usually follows the state process, often through an IRO the state assigns.

If your state does not run a program that meets the standards, or your type of plan is not covered by the state's rules, your review may go through the HHS-Administered Federal External Review Process instead. Some insurers contract directly with independent review organizations rather than using the state or federal route. You do not have to figure this out on your own — your final denial letter names the process that applies to you and tells you exactly where to file.

Not sure where any of this fits in the bigger picture? Start at the Fight Back home page for the full denial-to-appeal roadmap.