Medical Necessity Laws by State: Know Your Rights

Your rights when fighting a medical necessity denial depend heavily on where you live and what type of insurance you have. While federal laws set a floor, many states provide significantly stronger protections.

Federal Baseline: What Applies Everywhere

• ACA Section 2719: All non-grandfathered plans must provide internal appeal rights and access to external review.
• ERISA Section 503: Employer-sponsored plans must provide written denial reasons, at least one level of internal appeal, and access to the complete claim file.
• Mental Health Parity Act: Medical necessity criteria for mental health cannot be more restrictive than for medical/surgical benefits.
• No Surprises Act (2022): Establishes federal external review for certain out-of-network billing disputes.

States With the Strongest Protections

California

The Department of Managed Health Care (DMHC) oversees HMO appeals with binding authority. The Knox-Keene Act requires timely access to medically necessary care. Mandatory independent medical review (IMR) is available for all medical necessity disputes, and the insurer must pay for treatment during review if the denial involves an imminent health threat. California's external review overturn rate exceeds 60%.

New York

New York requires all health insurers to use the treating physician's definition of medical necessity rather than the insurer's internal guidelines. External review through the Department of Financial Services must be completed within 30 days (72 hours for urgent cases). Coverage for clinical trial participation costs is also mandated.

Illinois

Illinois requires coverage for any treatment consistent with generally accepted standards of medical practice. Independent review organization (IRO) decisions are binding. Strong mental health parity enforcement and mandatory autism spectrum disorder therapy coverage including ABA are also in place.

Texas

Texas has a mandatory IRO process for all medical necessity disputes. The Department of Insurance assigns a randomly selected IRO to each case. Texas law prohibits retroactive denials of pre-authorized treatments and includes "any willing provider" provisions.

Key State Protections to Look For

• Binding external review: In most states, the external reviewer's decision is binding on the insurer.
• Expedited review: Many states require 72-hour turnaround for urgent cases, some 24-hour for imminent threats.
• Treating physician deference: Some states require deference to the treating physician's medical judgment.
• Specialty reviewer requirements: Many states require external reviewers to be board-certified in the same specialty.
• Coverage during appeal: Some states require continued coverage while an appeal is pending.
• Off-label drug mandates: Over 40 states require coverage for off-label uses supported by recognized compendia.

How to Research Your State's Laws

1. Contact your state's Department of Insurance. Most have consumer assistance programs for appeals.
2. Check the NAIC website for state-by-state comparison tools.
3. Look at your state's Health Insurance Consumer Assistance Program for free help.
4. Review your plan's Evidence of Coverage, which must describe your appeal rights.

When writing your appeal, citing applicable state law strengthens your case. The insurer's legal and compliance team reviews appeals that reference specific statutes, signaling you are prepared to escalate. AppealArmor automatically identifies applicable state laws based on your location and plan type.