You pay for health insurance every month, but do you actually know what it covers? Many people are surprised to learn that their plan does not cover certain treatments they assumed were included, or that some services are available at no additional cost and they have never taken advantage of them.
The Affordable Care Act established a set of 10 categories of services that all marketplace plans and most small group plans must cover. These are called Essential Health Benefits. Understanding what they include, which protections attach to them, and — just as importantly — which kinds of plans are exempt from them is key to knowing what you are actually paying for.
The 10 Essential Health Benefits
Under the ACA, all individual and small group health insurance plans must cover these 10 categories of services.
1. Ambulatory Patient Services (Outpatient Care)
This covers medical care you receive without being admitted to a hospital, including doctor office visits, outpatient surgery, and same-day procedures. This is the category most people use most often.
2. Emergency Services
Emergency room visits are covered even if you go to an out-of-network hospital. Plans cannot charge higher copays or coinsurance for out-of-network emergency care, and they cannot require prior authorization for emergency services. Federal surprise-billing protections add a further layer: for emergency care, out-of-network providers generally cannot bill you beyond your in-network cost-sharing.
3. Hospitalization
This covers inpatient care when you are formally admitted to a hospital, including surgery, overnight stays, and intensive care. Watch the distinction between being admitted and being held for observation — observation stays are often billed as outpatient care, which can change what you owe.
4. Maternity and Newborn Care
Pregnancy coverage includes prenatal visits, labor and delivery, and postpartum care. Before the ACA, individual market plans frequently excluded maternity coverage entirely or sold it as an expensive rider. Now every ACA-compliant plan covers maternity care as a standard benefit, whether or not anyone on the policy expects to use it.
5. Mental Health and Substance Use Disorder Services
Plans must cover behavioral health treatment, including therapy, counseling, and inpatient mental health care, as well as substance use disorder services. Under the Mental Health Parity and Addiction Equity Act, plans cannot impose stricter limits on mental health benefits than on comparable medical or surgical benefits — no separate, lower visit caps and no harsher cost-sharing.
6. Prescription Drugs
Every plan must cover prescription medications, but not every medication. Plans maintain a formulary — a list of covered drugs organized into tiers with different cost-sharing — and must cover at least one drug in every federal category and class. If your medication is not on the formulary, you have the right to request an exception, and plans must have a process for it. Before enrolling in any plan, check its formulary against your actual prescriptions; two plans with identical premiums can differ by thousands of dollars a year for the same medicine cabinet.
7. Rehabilitative and Habilitative Services and Devices
Rehabilitative services help you recover skills you lost — physical therapy after surgery, speech therapy after a stroke. Habilitative services, a coverage category the ACA effectively created for the individual market, help people gain skills they never had, such as speech or occupational therapy for a child with a developmental delay. The category also covers devices such as wheelchairs and prosthetics. Visit limits are common here, so check the plan details if ongoing therapy matters to you.
8. Laboratory Services
Blood work, biopsies, and other diagnostic testing are covered. Note that where a test is performed matters: the same lab panel can cost dramatically more at a hospital outpatient department than at an independent lab, and your share follows the price.
9. Preventive and Wellness Services and Chronic Disease Management
This is the most underused benefit in American health insurance. ACA-compliant plans must cover a long list of preventive services at no cost to you — no copay, no deductible — when delivered by an in-network provider. The list includes annual wellness visits, immunizations, blood pressure and cholesterol screening, many cancer screenings such as colonoscopies and mammograms at recommended ages, depression screening, and contraception. If you are paying for insurance, these services are already part of the deal; the only mistake is not using them.
10. Pediatric Services, Including Dental and Vision
Children covered by ACA-compliant plans receive pediatric care including oral and vision benefits — routine dental checkups and eye exams for kids are part of the package, sometimes through a separate stand-alone dental plan sold alongside the medical plan.
What Essential Health Benefits Do Not Include
Knowing the boundaries prevents unpleasant surprises. Adult dental and vision care are not Essential Health Benefits. Neither, in general, are hearing aids for adults, long-term custodial care, cosmetic procedures, or most adult orthodontia. If you want adult dental or vision coverage, you typically buy it as a separate policy. Also, while every compliant plan must cover all 10 categories, the precise scope is set by a benchmark plan chosen in each state, so details — like how many therapy visits are covered — vary by state and by plan.
The Protections That Travel with Essential Health Benefits
The EHB framework comes bundled with structural protections that are easy to take for granted:
- No annual or lifetime dollar limits. Plans cannot cap the dollar amount they will pay for Essential Health Benefits over a year or a lifetime. Before the ACA, a serious illness could simply exhaust a policy.
- An out-of-pocket maximum. Your in-network spending on Essential Health Benefits is capped each year. For 2026, the limit is $10,600 for an individual and $21,200 for a family; most plans set theirs lower. After you hit it, the plan pays 100% of covered in-network care.
- No exclusions for preexisting conditions. Plans must cover you and your conditions from day one, with no waiting periods or medical underwriting.
Which Plans Are Exempt — and Why It Matters
Here is the part many shoppers miss: not everything sold as health coverage has to include Essential Health Benefits.
Large group and self-funded employer plans are not required to cover all 10 EHB categories, though in practice most cover the bulk of them, and the prohibition on annual and lifetime dollar limits still applies to any Essential Health Benefits they do cover. If you work for a large employer, your plan is governed primarily by federal employer-plan rules rather than the marketplace rulebook.
Short-term limited-duration plans are exempt entirely. They can exclude maternity care, mental health, and prescription drugs; impose dollar caps; and decline or surcharge applicants based on health history. Their low premiums reflect what they leave out.
Fixed indemnity products and health care sharing ministries are not health insurance in the regulatory sense at all. Indemnity products pay set cash amounts per event regardless of actual costs, and sharing ministries make no enforceable promise to pay anything. Both are sometimes marketed in ways that make them easy to mistake for comprehensive coverage.
None of this means such products are never useful — but they are categorically different from ACA-compliant insurance, and the difference shows up exactly when you are sickest.
Two further boundaries are worth a sentence each. A small number of grandfathered plans — policies that existed before the ACA passed and have changed little since — remain exempt from some requirements, including parts of the no-cost preventive care rule; if you have held the same policy for many years, ask your insurer whether it is grandfathered. And Medicare and Medicaid are governed by their own coverage rules, not the EHB framework: the categories overlap heavily, but the specifics — such as how drugs or therapy visits are covered — follow each program statute rather than the marketplace rulebook.
How to Check What Your Own Plan Covers
Every ACA-regulated plan must publish a Summary of Benefits and Coverage (SBC), a standardized document that lays out deductibles, the out-of-pocket maximum, and what you pay for common services, including worked examples. Read it before you enroll, and keep three habits afterward: verify that your doctors and hospital are in network for the specific plan (not just the insurance company), check the formulary for your medications each year since both can change at renewal, and when in doubt about a planned procedure, ask the plan in writing whether it is covered and whether prior authorization is required. Coverage disputes are far easier to win before care is delivered than after the bill arrives — and if a claim is denied, you always have the right to an internal appeal and then an independent external review.