Lab tests, X-rays, MRIs and CT scans: what you pay with Medicare

Lab tests

Medicare covers medically necessary lab tests your doctor orders, like certain blood tests, urinalysis, some tissue tests and some screenings. You generally pay nothing when the lab, pharmacy, doctor or hospital accepts assignment.

X-rays, MRIs, CT scans and other tests

• You pay 20% of the Medicare-approved amount after the Part B deductible.
• At a hospital outpatient department, you also pay the hospital a copay that may be more than 20%. In most cases it can't be more than the Part A hospital deductible ($1,736 in 2026) for each service.
• You may pay more at a hospital outpatient department than at an independent doctor's office for the same care. Medicare.gov's procedure price lookup can estimate costs.

Accredited providers for advanced imaging

Medicare only pays for certain scans, including CT, MRI, nuclear medicine and PET, from an accredited provider. If Medicare doesn't pay because the provider isn't accredited, the provider can't bill you for the test.

Blood

• If the provider gets blood from a blood bank at no charge, you don't pay for it or replace it, but you pay a copay for processing and handling each unit.
• If the provider has to buy blood, you pay for the first 3 units in a calendar year, or you or someone else can donate to replace it.

Screening tests like mammograms and colonoscopies have their own rules, often at no cost. See preventive care.