Medicare Preventive Services and Screenings Covered
Medicare covers a defined set of preventive services and screenings at no cost-sharing to eligible beneficiaries, meaning no deductible, copayment, or coinsurance applies when services are delivered correctly. These benefits span cardiovascular risk assessment, cancer detection, mental health screening, diabetes prevention, and immunizations. Understanding which services are covered, under what conditions, and how Original Medicare differs from Medicare Advantage in administering these benefits helps beneficiaries avoid unexpected bills and use their coverage effectively.
Definition and scope
Medicare's preventive services benefit is grounded in the Affordable Care Act of 2010, which eliminated cost-sharing for most preventive services rated "A" or "B" by the U.S. Preventive Services Task Force (USPSTF) when furnished by a participating provider. The statutory authority for Medicare preventive coverage is codified primarily under 42 U.S.C. § 1395x and related provisions of the Social Security Act, with administrative implementation managed by the Centers for Medicare & Medicaid Services (CMS).
The scope of covered preventive services under Medicare Part B is extensive. CMS publishes an annual update to the list, which as of the most recent CMS Preventive Services guidance includes more than 40 distinct screenings, counseling services, and immunizations. Services fall into three broad categories:
- Screenings — tests that detect conditions before symptoms appear (e.g., colorectal cancer screening, lung cancer screening, mammography, cervical cancer screening, abdominal aortic aneurysm screening)
- Counseling and behavioral interventions — structured conversations with a clinician on tobacco cessation, obesity, alcohol misuse, and cardiovascular disease prevention
- Immunizations — including influenza, pneumococcal, hepatitis B, and COVID-19 vaccines covered under Part B
Medicare Part A covers a narrower slice of preventive services, primarily limited to inpatient preventive care received during a covered hospital stay, whereas Part B carries the vast majority of outpatient preventive benefit.
How it works
A "Welcome to Medicare" preventive visit is available to new Part B enrollees within the first 12 months of enrollment. Beginning in the second year of enrollment, beneficiaries qualify for an Annual Wellness Visit (AWV) once every 12 months. The AWV is not a physical examination — CMS defines it as a structured review of medical history, current providers and suppliers, vital measurements, cognitive impairment detection, and the creation or update of a personalized prevention plan (CMS Medicare Learning Network, MLN006767).
For cost-sharing to be waived, two conditions must be met simultaneously:
- The claim must be submitted with the correct preventive service billing code (HCPCS or CPT code designated as preventive).
- The treating provider must be enrolled in Medicare and accept the Medicare-approved amount.
If a physician performs a separate diagnostic service during the same visit as a preventive screening — for instance, removing a polyp identified during a colonoscopy — cost-sharing rules for that additional service may apply separately. This distinction, sometimes called the "preventive-to-diagnostic conversion," is a frequent source of unexpected out-of-pocket costs documented by the Kaiser Family Foundation.
Medicare Advantage (Part C) plans are required by CMS to cover all services that Original Medicare covers, including preventive services with no cost-sharing. However, Advantage plans may also offer supplemental preventive benefits beyond Original Medicare's scope, such as dental cleanings or vision screenings, which Original Medicare does not cover. For a structured comparison of Original Medicare versus Advantage plan structures, see Medicare Advantage vs Original Medicare.
Common scenarios
Colorectal cancer screening: Medicare covers a colonoscopy once every 10 years for average-risk beneficiaries aged 45 and older, or once every 2 years for high-risk individuals. Flexible sigmoidoscopy is covered every 4 years. Stool-based tests (such as fecal occult blood tests) are covered annually. These intervals are established in CMS coverage determinations under the Medicare National Coverage Determination for colorectal cancer screening.
Mammography: Screening mammography is covered once every 12 months for women aged 40 and older. A baseline mammography is also available once to women aged 35–39.
Lung cancer screening: Low-dose computed tomography (LDCT) is covered annually for beneficiaries aged 50–77 who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years, per CMS NCD 210.14.
Diabetes prevention: The Medicare Diabetes Prevention Program (MDPP), established by CMS under the authority of Section 1115A of the Social Security Act, provides structured, CDC-recognized lifestyle change programs for beneficiaries at risk of type 2 diabetes.
Cardiovascular screening: Cardiovascular disease risk blood tests — including cholesterol, lipid, and triglyceride screening — are covered once every 5 years.
Decision boundaries
Not every service a physician recommends as preventive is automatically covered without cost-sharing. CMS applies strict billing rules: if a service does not carry an approved preventive billing code, or if the beneficiary's diagnosis shifts a claim from preventive to diagnostic, standard Part B cost-sharing applies. The Medicare costs, premiums, and cost-sharing structure determines the deductible and coinsurance rates that apply when a service is reclassified.
Beneficiaries enrolled in Medigap supplemental insurance may have diagnostic cost-sharing covered by their supplement plan, depending on plan type, but the preventive-to-diagnostic conversion itself is not altered by supplement enrollment.
Services that USPSTF rates "C," "D," or "I" are not automatically covered without cost-sharing under the ACA's zero cost-sharing mandate. CMS evaluates each service individually, and a "D" grade (the task force recommends against the service for that population) typically results in no Medicare coverage for that indication.
Beneficiaries seeking a complete overview of Medicare coverage scope — including what falls entirely outside coverage — can reference what Medicare does not cover alongside the full index of Medicare topics for structured navigation across all coverage dimensions.