ACA Essential Health Benefits Denied: What Must Be Covered and How to Fight Back

One of the ACA's most significant consumer protections is the Essential Health Benefits (EHB) mandate. Under the Affordable Care Act, all non-grandfathered individual and small group health plans — including ACA marketplace plans — must cover a defined set of health services. If your claim falls within one of the 10 EHB categories and was denied, the denial may be unlawful.

What Are the 10 Essential Health Benefit Categories?

Under 42 U.S.C. §18022, the 10 EHB categories are:

1. Ambulatory patient services — outpatient care you receive without being admitted to a hospital
2. Emergency services — emergency room visits and stabilization
3. Hospitalization — inpatient care including surgery
4. Maternity and newborn care — prenatal care, labor and delivery, newborn care
5. Mental health and substance use disorder services — including behavioral health treatment, psychotherapy, and inpatient mental health
6. Prescription drugs — at least one drug per category in the USP drug classification system
7. Rehabilitative and habilitative services and devices — services to recover skills after illness or injury (rehabilitative) and to help those who never acquired certain skills (habilitative, like speech therapy for developmental delays)
8. Laboratory services
9. Preventive and wellness services and chronic disease management — USPSTF Grade A/B recommendations, ACIP vaccine recommendations, HRSA preventive guidelines for women and children
10. Pediatric services — including oral and vision care for children

Plans cannot maintain annual or lifetime dollar limits on essential health benefits, and they cannot categorically exclude entire EHB categories.

How EHBs Are Defined: The Benchmark Plan

Here's where it gets nuanced. The ACA delegates defining the specifics of each EHB category to the states. Each state selects a benchmark plan — typically based on the largest small group insurer plan in the state or a state employee plan — and that benchmark plan defines the scope of EHBs in that state.

This means two plans in different states may have different EHB benchmarks. For example:

• Habilitative services (speech, occupational, physical therapy for developmental conditions) may be covered at parity with rehabilitative services in one state but more narrowly in another
• Mental health inpatient days may be treated differently depending on the benchmark
• Specific prescription drug coverage may vary

To find your state's benchmark plan, search the CMS website for your state's EHB benchmark plan documentation.

Habilitative Services: A Frequently Disputed EHB

Habilitative services — designed to help develop skills that were never acquired due to a disability or developmental condition — are among the most commonly disputed EHBs. Unlike rehabilitative services (which restore lost function), habilitative services help with conditions like:

• Autism spectrum disorder (ABA therapy)
• Cerebral palsy
• Down syndrome
• Developmental delays in children

Many plans historically limited or excluded habilitative services, but ACA requires coverage. The scope may be defined by your state's benchmark plan, but a flat exclusion of habilitative services is impermissible. If your ABA therapy, speech therapy, or occupational therapy is being denied as "not a covered benefit," check whether this falls within your state's EHB benchmark for habilitative services.

Maternity Care: A Protected EHB

Maternity and newborn care is an EHB that pre-ACA individual plans frequently excluded. If your marketplace plan is denying prenatal care, labor and delivery, or newborn care as "not covered" or through unreasonable Prior Authorization Denied: How to Appeal" class="auto-link">prior authorization requirements, this is legally vulnerable. The newborn's first physician visit typically qualifies under this category as well.

Preventive Care: First-Dollar Coverage Required

ACA marketplace plans must cover USPSTF Grade A and B preventive services at no cost to you — meaning no copay, deductible, or coinsurance. This includes colonoscopies, mammograms, blood pressure and cholesterol screening, certain vaccines, and others.

If your plan charged you cost-sharing for a preventive service, file a complaint with your state insurance commissioner or HHS. This is a straightforward ACA violation when it occurs.

Note: The Supreme Court's Braidwood Management v. Becerra decision (2024) addressed the constitutionality of some preventive care mandates. Check current HHS guidance for the current status of specific preventive care coverage requirements.

How to Appeal an EHB Denial

Step 1: Identify the EHB category. Match your denied service to one of the 10 EHB categories. If it fits, note the specific category and the ACA statutory citation: 42 U.S.C. §18022.

Step 2: Find your state's EHB benchmark. If the question is whether your specific service is within the EHB, look at your state's benchmark plan description. CMS publishes EHB benchmark information at cms.gov.

Step 3: Document medical necessity. Even EHB services can be denied as not medically necessary. A strong physician letter and clinical documentation are essential.

Step 4: Appeal internally, citing the EHB mandate. Your internal appeal letter should state: "The denied service [X] falls within the [EHB category] essential health benefit required under 42 U.S.C. §18022 and [state] benchmark plan provisions. The plan cannot categorically exclude services within this EHB category."

Step 5: Request External Independent Review: Complete Guide" class="auto-link">external review. IROs reviewing EHB disputes apply ACA standards, not just the plan's internal coverage policies. External review is particularly valuable for EHB disputes.

Step 6: File regulatory complaints. State insurance departments and HHS/CMS accept complaints about EHB violations.

Fight Back With ClaimBack

EHB denials are among the clearest cases where federal law is firmly on your side. ClaimBack helps you identify the applicable EHB category, build a compelling appeal citing ACA authority, and escalate through all available channels.

Start your appeal at ClaimBack

Related Reading:

• How to Write an Insurance Appeal Letter
• What Is Medical Necessity?
• Common Reasons Insurance Claims Are Denied