What Medicare Does Not Cover

Medicare provides broad health coverage for tens of millions of Americans aged 65 and older, as well as qualifying individuals with disabilities, but the program carries significant statutory exclusions that directly affect out-of-pocket costs and care planning. Understanding what Medicare does not cover is essential for anticipating expenses that beneficiaries must fund through supplemental insurance, personal savings, or other programs. This page identifies the major categories of non-covered services, explains how exclusions are determined, and maps the decision boundaries that separate covered from non-covered care.

Definition and Scope

Medicare's coverage exclusions are defined primarily under Section 1862 of the Social Security Act (42 U.S.C. § 1395y), which lists services and items that the program will not pay for regardless of medical necessity claims. These exclusions apply across Original Medicare (Parts A and B) and are not automatically resolved by enrolling in a Medicare Advantage plan, though some Medicare Advantage plans do voluntarily extend coverage into certain excluded categories as supplemental benefits.

The scope of non-covered services is substantial. According to the Medicare & You handbook published annually by the Centers for Medicare & Medicaid Services (CMS), the following categories represent the most consequential statutory exclusions:

1. Long-term custodial care — Skilled nursing facility coverage under Medicare Part A is limited to a maximum of 100 days per benefit period and only follows a qualifying inpatient hospital stay of at least 3 consecutive days. Custodial care — assistance with daily activities such as bathing, dressing, and eating — is explicitly excluded.
2. Routine dental care — Exams, cleanings, fillings, tooth extractions, dentures, and dental plates are not covered under Original Medicare.
3. Routine vision care — Standard eye exams for prescribing eyeglasses, contact lenses, and corrective lenses themselves are excluded (though treatment of disease conditions such as glaucoma or diabetic retinopathy may qualify).
4. Hearing aids and routine hearing exams — Hearing aids and the fitting exams specific to them are not covered, even when hearing loss is medically documented.
5. Cosmetic surgery — Procedures performed solely for cosmetic purposes are excluded, though reconstructive surgery following injury or illness may qualify.
6. Acupuncture — Covered only in the limited context of chronic low back pain treatment, per a 2020 CMS national coverage determination; broader acupuncture use remains excluded.
7. Most prescription drugs outside hospital settings — Medicare Part B covers certain drugs administered in clinical settings, but outpatient prescriptions generally require separate Part D enrollment.
8. Care received outside the United States — With narrow exceptions for emergency care in Canada or Mexico under specific geographic conditions, Medicare does not pay for services delivered abroad.

How It Works

The exclusion mechanism operates through the claims adjudication process. When a provider submits a claim to CMS or a Medicare Administrative Contractor (MAC), each line item is evaluated against the National Coverage Determinations (NCDs) and Local Coverage Determinations (LCDs) maintained by CMS. A service falling under a statutory exclusion at 42 U.S.C. § 1395y is denied at the first level of review.

Providers who deliver services they know or reasonably expect are non-covered are required to issue an Advance Beneficiary Notice of Noncoverage (ABN) before service delivery. The ABN shifts financial liability to the beneficiary. If the provider fails to issue a proper ABN, the provider — not the beneficiary — absorbs the cost. CMS publishes ABN requirements and the standardized form (CMS-R-131) through its Medicare Learning Network.

Exclusions are distinct from coverage gaps. A coverage gap (such as the Part D prescription drug coverage gap) involves a temporary reduction in benefit payment within an otherwise covered category. An exclusion means the category of service is entirely outside the program's statutory authority to pay. For a deeper look at how gaps differ from exclusions, the Medicare Coverage Gaps topic provides additional context.

Common Scenarios

Three scenarios illustrate how exclusions affect beneficiaries in practice:

Scenario 1: Long-Term Care Transition
A beneficiary discharged from a hospital after a 5-day stay may qualify for up to 100 days of skilled nursing facility (SNF) care under Part A, with a $200 per day copayment for days 21–100 in 2024 (CMS Medicare Cost Report). Once the skilled care need ends or the 100-day limit is reached, ongoing custodial care becomes 100% the beneficiary's financial responsibility.

Scenario 2: Dental Following Cancer Treatment
A beneficiary requiring tooth extractions before radiation therapy for oral cancer may find that Medicare covers the radiation treatment but not the extractions themselves, even when the dental work is medically required to proceed safely with the covered treatment.

Scenario 3: Hearing Loss in an Aging Beneficiary
Audiologist diagnostic evaluations ordered by a physician to assess hearing loss may qualify under Part B, but the hearing aid device and fitting exam do not. The beneficiary must fund the device — which averages over $2,000 per ear at retail — independently or through a supplemental plan.

Beneficiaries seeking coverage for these scenarios often explore Medicare Supplement Insurance (Medigap), Medicare Advantage plans with added benefits, or low-income assistance programs depending on financial eligibility.

Decision Boundaries

Determining whether a specific service is excluded requires evaluating three thresholds:

Statutory vs. administrative exclusion: Statutory exclusions under 42 U.S.C. § 1395y cannot be overridden by CMS administrative action. Administrative limitations (such as visit caps or prior authorization requirements) can be waived or modified through regulatory processes.

Custodial vs. skilled care: This is the most contested boundary in long-term care. Medicare covers skilled nursing, skilled therapy, and medically necessary care provided by licensed professionals. The moment care becomes primarily maintenance or assistance with daily living activities — regardless of how the provider labels it — the statutory custodial exclusion applies. CMS guidance under the Jimmo v. Sebelius settlement clarified that improvement potential is not required for skilled care coverage, but the skilled-vs.-custodial distinction remains.

Covered condition vs. excluded service: A service may treat a covered condition yet still be excluded. Dental extractions preceding cancer radiation treatment illustrate this clearly — the exclusion attaches to the service category, not to the underlying medical purpose.

Beneficiaries who believe a claim was incorrectly denied as an exclusion have formal appeals rights under Medicare. A denial based on a coverage exclusion follows a distinct appeals pathway from a denial based on medical necessity. The full overview of Medicare's structure, including where exclusions fit within the program's broader framework, is available through the National Medicare Authority homepage.