Medicare health insurance premiums can add up to big bucks — especially if you’re upper-income, married, and you and your spouse both pay premiums. Read on to understand how taxes fit in. Premiums for Part B coverage Medicare Part B coverage is commonly called Medicare medical insurance. Part B mainly covers doctors’ visits and outpatient services. Eligible individuals must pay monthly premiums for this benefit. Medicare is generally for people 65 or older. It’s also available earlier to some people with disabilities, and those with end-stage renal disease and ALS. The monthly premium for the current year depends on your modified adjusted gross income (MAGI), as reported on your Form 1040 for two years earlier. MAGI is the adjusted gross income (AGI) number on your Form 1040 plus...