Patient Rights When an Insurance Claim Is Denied

A denied insurance claim can feel like the end of the road — but under federal and state law, it is actually the beginning of a formal process with specific timelines, required notices, and enforceable rights at every step. This page covers what a denial means legally, how the internal and external appeal process works, what scenarios trigger the strongest protections, and where the rules draw firm lines between a health plan's discretion and a patient's guaranteed rights.

Definition and scope

A coverage denial occurs when a health insurer refuses to pay for a service, either before it happens (a prior authorization denial) or after the fact (a claim denial on an Explanation of Benefits). The distinction matters. A prior authorization denial gives a patient the chance to fight before incurring costs; a post-service claim denial means a bill may already be sitting on the kitchen table.

Federal protections apply differently depending on the type of insurance. The Affordable Care Act established a uniform appeals framework for most private plans — including employer-sponsored coverage — requiring insurers to offer at least one internal appeal and one external review by an independent organization. Medicare and Medicaid operate under separate federal frameworks with their own timelines and review bodies. Together, these systems cover the majority of insured Americans, though the exact rules vary by plan type and state.

The grievance and appeals process is the formal machinery that converts a denial into a reviewable decision. Without understanding that machinery, a patient is essentially sending complaint letters into a void.

How it works

Federal rules under the ACA (45 CFR § 147.136) require non-grandfathered health plans to follow a structured sequence when a claim is denied.

  1. Written notice of denial. The plan must provide a written explanation stating the specific reason for denial, the clinical criteria or plan provisions used, and information about how to appeal.
  2. Internal appeal. The enrollee has the right to a full and fair internal review. For urgent care denials, the plan must respond within 72 hours. For standard non-urgent appeals, the deadline is 30 days for pre-service denials and 60 days for post-service denials.
  3. External Independent Medical Review (IMR). If the internal appeal fails — or if the plan doesn't respond within required timeframes — the enrollee can request review by an independent organization accredited under state or federal standards. External reviewers are not employed by the insurer; their decisions on medical necessity are binding on the plan in most states.
  4. State Insurance Commissioner complaint. Running parallel to appeals, enrollees can file complaints with their state's insurance department at any stage. Many states have additional consumer protections that exceed federal minimums.

The federal agencies enforcing patient rights, including the Centers for Medicare & Medicaid Services (CMS) and the Department of Labor for employer plans, maintain oversight authority when plans fall out of compliance with these timelines.

Common scenarios

Three denial types account for the overwhelming majority of patient disputes.

Medical necessity denials are the most common. The insurer agrees the service exists in the policy but argues it isn't medically necessary for this patient. These are the strongest candidates for external review, because an independent physician can directly contradict the insurer's clinical rationale. The right to a second opinion is relevant here — documentation from a second treating physician often strengthens an appeal significantly.

Prior authorization failures occur when a provider submits an authorization request and the plan denies it before treatment begins — or, more frustratingly, when a provider fails to submit one at all and the patient learns about the gap only after receiving care. Some states have enacted "gold carding" laws that exempt physicians with strong compliance records from routine prior authorization requirements entirely.

Out-of-network billing disputes arise when a patient receives care from a provider the plan doesn't consider in-network, or when a surprise bill arrives from an out-of-network provider at an in-network facility. The No Surprises Act, enacted in 2020 and implemented through regulations finalized by CMS, established an independent dispute resolution process specifically for these situations, limiting patient cost exposure to in-network cost-sharing amounts in most emergency contexts (CMS, No Surprises Act Overview).

Decision boundaries

Not every denial can be fully reversed, and the law draws clear lines between what a plan controls and what a patient can enforce.

Coverage exclusions vs. medical necessity. If a service is flatly excluded from a policy — cosmetic surgery unrelated to a covered condition, for example — an external reviewer generally cannot override that exclusion. The external review process applies to medical necessity determinations and clinical judgment calls, not to contractual exclusions. Reading the Summary of Benefits and Coverage document, which plans are required to provide under the ACA, is essential for distinguishing these two categories.

ERISA-governed employer plans vs. fully insured state-regulated plans. This is the sharpest dividing line in American health insurance. Self-funded employer plans — which cover roughly 65 percent of privately insured workers, according to the Kaiser Family Foundation's 2023 Employer Health Benefits Survey — are governed by the Employee Retirement Income Security Act (ERISA) and are largely exempt from state insurance laws. Patients in ERISA plans have access to federal external review under ACA regulations but face a narrower set of state remedies than patients in fully insured plans.

Exhaustion of remedies. Courts have consistently required that enrollees exhaust internal appeals before filing suit, with limited exceptions for futility. The patient rights and insurance denials framework makes exhaustion a practical prerequisite, not just a formality. Skipping an internal appeal step can eliminate legal options entirely.

The broader landscape of rights that intersect with insurance disputes — including privacy rights during the appeals process and rights specific to mental health coverage parity — is outlined across the National Patient Rights Authority resource library.

References