Health Insurance Claims: Submission, Review, and Appeals

Health insurance claims are the formal mechanism through which policyholders and healthcare providers request reimbursement from an insurer for covered medical services. This page covers the full lifecycle of a health insurance claim — from initial submission through internal review and formal appeals — and addresses the regulatory frameworks that govern each phase. Understanding this process is essential for navigating denials, managing timelines, and exercising statutory rights under federal and state law.

Definition and Scope

A health insurance claim is a request submitted to a health plan asking the insurer to pay for medical services rendered to a covered individual. Claims can be filed by the healthcare provider directly (assignment of benefits) or by the policyholder after paying out of pocket. The scope of health insurance claims spans employer-sponsored group plans regulated under the Employee Retirement Income Security Act of 1974 (ERISA, 29 U.S.C. § 1001 et seq.), individual market plans subject to the Affordable Care Act (ACA, 42 U.S.C. § 18001 et seq.), Medicare administered by the Centers for Medicare & Medicaid Services (CMS), and Medicaid programs operated jointly by CMS and individual states.

The insurance claims process overview for health claims differs meaningfully from property or casualty lines because adjudication is governed by clinical criteria and coding standards in addition to policy language. The American Medical Association's Current Procedural Terminology (CPT) code set and the ICD-10-CM diagnosis coding system published by CMS are the two primary classification frameworks used to translate medical encounters into billable claims.

How It Works

Health insurance claims follow a structured adjudication sequence with discrete phases:

1. Service and documentation capture. At the point of care, the provider records the encounter using CPT procedure codes and ICD-10-CM diagnosis codes. Patient eligibility is verified against the insurer's eligibility database before or at the time of service.

2. Claim submission. The provider submits an electronic claim via the HIPAA-standardized 837P (professional) or 837I (institutional) transaction format, as mandated under 45 CFR Part 162 (HIPAA Administrative Simplification). Paper claims use the CMS-1500 form for professional services or the UB-04 for facility claims.

3. Initial adjudication. The insurer's claims processing system applies edits to check for duplicate claims, coding accuracy, member eligibility, and coverage applicability. This automated review occurs before a human adjudicator is engaged.

4. Medical necessity review. Claims for procedures flagged by the insurer's clinical guidelines — such as inpatient admissions, specialty referrals, or high-cost imaging — may be routed to utilization management. Insurers apply internally adopted clinical criteria (frequently InterQual or Milliman Care Guidelines) to assess medical necessity.

5. Explanation of Benefits (EOB) issuance. The insurer issues an EOB to the member and a remittance advice to the provider detailing the adjudication outcome: paid amount, contractual adjustment, member cost-sharing, and any denial reason codes.

6. Payment or denial. Under the ACA, non-grandfathered plans must adhere to internal claims and appeals procedures established at 45 CFR § 147.136, which set maximum timeframes for claim decisions.

Regulatory timeframes matter significantly: urgent care claims must receive a decision within 72 hours, pre-service claims within 15 days (extendable once by 15 days), and post-service claims within 30 days (extendable once by 15 days) under 45 CFR § 147.136.

Common Scenarios

Three claim scenarios account for the largest share of health insurance disputes:

In-network vs. out-of-network claims. When a member receives care from a provider outside the plan's contracted network, the claim is processed at out-of-network benefit levels, which typically carry higher cost-sharing. For emergency services, however, the No Surprises Act (Pub. L. 116-260), enacted as part of the Consolidated Appropriations Act, 2021 (enacted December 27, 2020), prohibits balance billing from out-of-network providers and requires insurers to apply in-network cost-sharing effective for plan years beginning on or after January 1, 2022.

Prior authorization denials converted to claims denials. A service may receive prior authorization, yet the resulting claim is denied for coding discrepancies between the authorized procedure and the procedure actually billed. This scenario is particularly common with surgical claims and requires reconciliation between the authorization number and the claim submission. Readers navigating this type of denial will find the insurance claim denial reasons resource useful for identifying specific denial codes.

Coordination of benefits (COB) disputes. When a member is covered under two health plans — such as an employee plan and a spouse's plan — the insurer applies COB rules under the NAIC Model Coordination of Benefits Regulation to determine which plan pays primary and which pays secondary. Errors in COB sequencing generate underpayments and pended claims that require manual intervention.

Decision Boundaries

The insurance claim appeals process for health plans is a two-tier federal minimum standard under 45 CFR § 147.136: internal appeal followed by external review.

Internal appeals must be decided within 60 days for post-service claims and 30 days for pre-service claims. The insurer must provide the claimant with the specific reason for denial, including the clinical criteria and plan provisions relied upon, and must make the claim file available free of charge upon request.

External review is available for denials involving medical judgment or rescission of coverage. Under the federal external review process (applicable when a state's external review program does not meet federal standards), an Independent Review Organization (IRO) accredited under standards recognized by the Department of Health and Human Services makes a binding determination. ERISA-governed plans follow a parallel but distinct external review pathway.

The key distinction between ERISA and non-ERISA plans is remedial scope: ERISA plan participants are limited to federal court remedies under 29 U.S.C. § 1132, which generally precludes punitive damages, while state-regulated individual and fully-insured group plans may be subject to state insurance bad faith statutes. Detailed classification of types of insurance claims and the insurance claim documentation requirements that apply to each can affect which remedial path is available.

References

• U.S. Department of Labor — ERISA Overview
• U.S. Department of Health and Human Services — Affordable Care Act
• Centers for Medicare & Medicaid Services (CMS)
• CMS — No Surprises Act
• Electronic Code of Federal Regulations — 45 CFR § 147.136 (Internal Claims and Appeals)
• Electronic Code of Federal Regulations — 45 CFR Part 162 (HIPAA Administrative Simplification)
• American Medical Association — CPT Code Set
• NAIC — Coordination of Benefits Model Regulation