Part B (Medical Insurance)

Medicare Part B is the medical insurance half of Original Medicare. It covers doctor visits, outpatient hospital care, preventive screenings, lab tests, mental health services, and durable medical equipment like walkers and wheelchairs. Unlike Part A, almost everyone pays a monthly premium for Part B.

For beneficiaries, Part B is where most everyday health costs run through. After you meet the annual Part B deductible ($257 in 2025), you typically pay 20% coinsurance of the Medicare-approved amount — with no cap on that 20%. Higher-income enrollees pay an IRMAA surcharge on top of the standard premium. Because there is no out-of-pocket maximum, a single serious illness can lead to thousands of dollars in coinsurance.

For example, if you have outpatient surgery with a $10,000 Medicare-approved cost, your 20% share is $2,000 — and you would owe 20% again on the next service. A Medigap plan or a Medicare Advantage plan with an out-of-pocket cap is how most people limit this exposure.

Have questions about Part B? Get a free Medicare review and we will help you understand your premium, deductible, and the best way to cover the 20% coinsurance.