What is Medicare Part B?
Part B helps cover medical services like doctors' services, outpatient care, and other medical services that Part A doesn't cover. Part B is optional. Part B helps pay for covered medical services and items when they are Medically Necessary (see Part B Helps Cover These Items and Services ). Part B also covers some Preventive Services.Cost: You pay the Part B Premium each month (see Your 2026 Monthly Premiums for Medicare for the 2026 amount). In some cases, this amount may be higher if you didn't sign up for Part B when you first became eligible.
You also pay a Part B Deductible each year before Medicare starts to pay its share. See What you pay for the Original Medicare Plan in 2026 - Part B for the 2026 amount. You may be able to get help from your state to pay this premium and deductible (see Medicare Savings Programs (help from Medicaid paying Medicare premiums)).
If you don't take Part B when you are first eligible, the cost of Part B will go up 10% for each full 12-month period that you could have had Part B but didn't sign up for it, except in special cases (see Special Enrollment Period (SEP)). You may have to pay this Penalty as long as you have Part B.
If you didn't sign up for Part B when you first became eligible, call Social Security at 1-800-772-1213 to see when you can apply. TTY users should call 1-800-325-0778. If you get benefits from the Railroad Retirement Board (RRB), call your local RRB office or 1-800-808-0772.
(Primary Source: Centers for Medicare and Medicaid Services - Medicare and You Handbook. This content may have been enhanced by this site to include further examples, explanations, and links.)