How to Request External Review After an Insurance Denial
What External Review Is — and Why It Matters
Key Takeaway: External review is the final step in the formal insurance appeal process before litigation. An independent reviewer — not your insurer — evaluates whether the denial was correct. For eligible plans, the external reviewer's decision is binding on the insurer and cannot be overridden.
When an insurer denies a claim — whether for medical necessity, prior authorization, or an experimental treatment — the internal appeal process gives you one or more opportunities to present your case to the insurer itself. External review goes further: an independent organization with no financial relationship to your insurer reviews the same claim and applies the same clinical standards. If the external reviewer finds the denial was wrong, your insurer must provide coverage.
The right to external review for non-grandfathered individual and group health insurance plans is established under ACA §2719 and Healthcare.gov external review guidance. CMS has published implementing regulations establishing minimum standards for external review programs, including which plans must offer external review, who qualifies, how to file, and how decisions are made.
External review is distinct from filing a complaint with your state insurance commissioner — commissioner complaints can trigger investigations of insurer practices but do not directly result in coverage decisions on your individual claim. External review produces a binding coverage determination for your specific claim.
Which Plans Are Covered by ACA External Review
Key Takeaway: ACA external review rights apply to non-grandfathered individual and group market health insurance plans. Grandfathered plans (those in effect before March 23, 2010 that have not made significant changes) may have different external review requirements. Medicare has its own five-level appeal system and is not covered by ACA external review.
| Plan Type | External Review Available? | Governing Process |
|---|---|---|
| ACA marketplace (individual) — non-grandfathered | Yes | State external review program or federal (HHS/Maximus) process; ACA §2719 |
| Employer group plans — non-grandfathered, fully insured | Yes | State external review (applies to fully insured plans in most states); ACA §2719 |
| ERISA self-insured employer plans | Yes (federal process) | Federal external review process per DOL technical release; state external review laws generally preempted by ERISA |
| Grandfathered plans | Varies | ACA external review does not automatically apply; check plan documents and state law |
| Medicare (Original, Advantage, Part D) | No — separate system | Medicare's five-level appeal process (MAC redetermination → QIC → ALJ → MAC → federal court) |
| Medicaid managed care | Varies by state | State fair hearing process; Medicaid managed care external review requirements vary by state |
Do not confuse Medicare and ACA external review. Medicare beneficiaries have a completely separate appeal system that predates and is independent of the ACA external review process. Sending an external review request to an ACA IRO for a Medicare claim will not be processed — you must use Medicare's appeal system. The two systems do not overlap.
What Types of Denials Are Eligible for External Review
Key Takeaway: External review covers adverse benefit determinations based on medical judgment — medical necessity, appropriateness, experimental or investigational treatment. Purely contractual exclusions (a benefit simply not listed in the plan document) may not qualify. Understanding which category your denial falls into determines whether external review is available.
The ACA external review regulations distinguish between two categories of denials:
- Medical judgment denials: The insurer determined that the service or treatment does not meet medical necessity, medical appropriateness, healthcare setting, or level-of-care criteria; or that the treatment is experimental or investigational. These denials are eligible for external review because they involve clinical judgment that an independent medical reviewer can assess.
- Rescissions: If the insurer retroactively cancels your coverage (rescission), external review is also available — even if no internal appeal was completed.
- Contractual exclusions: If the plan document simply states that a specific benefit (e.g., “weight loss drugs are excluded”) is not covered, the denial may be characterized as a contractual exclusion rather than a medical judgment. Contractual exclusions are generally not eligible for external review on medical necessity grounds. However, if the insurer applied its medical necessity criteria in denying the claim — not just citing a categorical exclusion — it may still be eligible. Review the specific language in your denial letter.
If your denial involves a prior authorization denial or a medical necessity determination for care that the plan covers in principle, it is almost certainly eligible for external review. For prior authorization appeal strategy, see our guide on how to appeal a prior authorization denial.
How to File for External Review: Step-by-Step
Key Takeaway: The external review request process is straightforward but time-sensitive. Your final internal denial notice must include instructions — follow them precisely. Missing the filing deadline forfeits your right to external review.
Follow these steps after receiving your final internal appeal denial:
- Read the final denial notice: It must include your right to external review, who to contact (the insurer's external review administrator or HHS/Maximus for the federal process), and the filing deadline. The deadline is typically 4 months (approximately 120 days) from the date of the final internal denial notice.
- Determine whether to use the state or federal process: In most states, ACA-regulated plans connect to a state-approved IRO program. If your state does not have an approved external review program or your plan is subject to the federal process (common for self-insured ERISA plans), you may file through the CMS CCIIO external appeals program or contact your state insurance department.
- Submit the external review request: Typically in writing (mail, fax, or online form per the insurer's instructions). Include: claim reference number, the denial letter, your medical documentation, and a brief explanation of why you believe the denial is wrong.
- Insurer forwards the claim file: Once the IRO is assigned, the insurer must forward your complete claim file — including all clinical documentation and the basis for the denial — to the IRO within a specified timeframe.
- Submit additional evidence: You may submit additional medical documentation directly to the IRO. Do so promptly — the IRO's review timeline starts immediately.
- Await the IRO decision: Standard review: decision within 45 days of IRO receiving the request. Expedited review: within 72 hours.
Urgent External Review: Expedited Process for Time-Sensitive Claims
Key Takeaway: If waiting 45 days for standard external review would seriously jeopardize your health, ability to regain maximum function, or ability to function, you can request expedited external review. The IRO must decide within 72 hours. Expedited external review can be requested simultaneously with an internal appeal for the most urgent situations.
Expedited external review is available when:
- The standard external review timeframe would seriously jeopardize your life, health, or ability to regain maximum function — for example, a denial of an inpatient hospital admission, ongoing cancer treatment, or a necessary surgical procedure.
- The denial involves a concurrent review determination (ongoing inpatient treatment) and you request expedited review before discharge or termination of the authorized level of care.
For truly urgent situations — where the denial concerns ongoing treatment — you can request expedited external review simultaneously with the internal appeal, without waiting for the internal appeal to conclude. This is an exception to the general rule that internal appeals must be exhausted first.
Expedited external review decisions must be communicated to you immediately (by phone or electronic communication) and followed up in writing. If the IRO overturns the denial, the insurer must provide coverage immediately.
Documents to Submit with Your External Review Request
Key Takeaway: Submit the strongest possible clinical record with your external review request. The IRO reviews the same evidence the insurer had, plus anything you add. New clinical evidence you provide after the internal appeal can strengthen the external review outcome.
| Document | Why Include It |
|---|---|
| Final internal denial notice | Establishes the decision being reviewed; identifies the clinical criteria the insurer applied |
| All prior internal appeal submissions | Provides the IRO with the complete record the insurer reviewed |
| Updated treating provider letter | Addresses the specific denial criterion; may include new clinical information unavailable at the time of the internal appeal |
| Clinical guidelines or peer-reviewed literature | Shows that the denied care is consistent with accepted medical standards; IROs apply clinical standards in their review |
| Any new diagnostic results or records | New objective evidence that may not have been part of the internal appeal record |
| Written explanation of the claim | Brief, factual summary of: what was denied, why you believe it qualifies for coverage, and specific errors in the insurer's clinical reasoning |
Medicare Appeals: A Completely Different System
Key Takeaway: Medicare does not use the ACA external review process. Medicare beneficiaries have a five-level appeal system with different organizations, timelines, and dollar thresholds at each level. Medicaid managed care uses a state fair hearing process. Never assume your Medicare or Medicaid appeal rights are the same as ACA commercial plan external review.
According to Medicare.gov's appeals guidance, the five-level Medicare appeals process is:
- Redetermination by the Medicare Administrative Contractor (MAC) — file within 120 days of receiving the initial determination. Decision within 60 days.
- Reconsideration by a Qualified Independent Contractor (QIC) — file within 180 days of the MAC redetermination. Decision within 60 days (standard) or 72 hours (expedited).
- ALJ hearing — available if the amount in controversy meets the annual threshold (adjusted by CMS). File within 60 days of QIC reconsideration.
- Medicare Appeals Council review — file within 60 days of ALJ decision.
- Federal district court — if the amount in controversy meets the threshold.
Medicare Advantage (Part C) and Part D have parallel appeal structures with the same escalation levels but different organization names and timelines at certain steps. For Medicare-specific denials, check Medicare.gov for current timelines — the dollar thresholds for ALJ hearings are adjusted annually.
Prepare Your External Review Submission
AppealFlow generates formal appeal letters for prior authorization, medical necessity, and prescription denials — the same letters you can submit to both your insurer's internal appeal and an external review organization.
What Happens After the External Review Decision
Key Takeaway: An external review decision to overturn a denial is binding on the insurer — the plan must provide coverage consistent with the IRO's decision. If the IRO upholds the denial, you have exhausted the administrative appeal process for most plan types; further options may include filing with your state insurance commissioner or consulting an attorney for ERISA or bad-faith claims.
If the IRO overturns the denial: the insurer must provide the coverage or benefit as determined by the external reviewer. If the denied care has not yet been provided, the insurer must authorize it. If the care was provided and the bill was denied, the insurer must pay the claim. The insurer cannot appeal the external reviewer's decision.
If the IRO upholds the denial: you have exhausted the external administrative appeal process for that claim. Further options include:
- State insurance department complaint: If you believe the insurer violated state law (e.g., bad faith, mental health parity, step therapy law), file a complaint with your state's insurance commissioner. This can trigger a regulatory investigation but does not directly produce a coverage decision on your claim.
- ERISA civil action: For ERISA employer plans, if you have exhausted administrative remedies, you may be able to file suit in federal district court under ERISA §502(a) to recover benefits. ERISA litigation is complex — consult an ERISA attorney before filing.
- State insurance court action: For fully insured plans, state bad-faith insurance claims may be available in addition to or instead of ERISA claims. State insurance bad-faith law varies significantly — consult a state-licensed attorney.
For medical necessity and prior authorization denials that have not yet reached external review, see our tools for medical necessity appeals and prior authorization appeals.
Frequently Asked Questions
Common questions about external review rights, eligibility, how to file, ACA vs. ERISA processes, and how Medicare appeals differ from ACA external review.
Generate Your Free Appeal Letter
AppealFlow drafts formal insurance appeal letters for medical necessity, prior authorization, and prescription denials — citing ACA §2719, ERISA §503, and your specific denial reason. Use the same letter for internal appeals and external review submissions. Edit live, download as PDF or Word. No account required.
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Disclaimer: This article is for educational purposes only and does not constitute medical, legal, or financial advice. AppealFlow.net is not a healthcare provider, insurance broker, or law firm. External review rights depend on your plan type and state — verify your specific rights in your plan documents and denial letter. ACA external review guidance is available from Healthcare.gov and CMS CCIIO. Medicare appeals guidance is at Medicare.gov. ERISA claims procedure regulations are at DOL EBSA. See our full disclaimer.