A: Medicare Part A (hospital insurance) is free for most seniors. If you or your spouse worked at least 10 years in a job where you paid Medicare taxes, you’re eligible for free Medicare Part A when you turn 65. Medicare A is also free for people under 65 who have been on Social Security disability for at least two years, or who have end-stage renal disease. Although most Medicare beneficiaries receive Part A with no premium, if you do have to pay for it, the premium in 2018 is $422 per month if you worked less than 7.5 years, and $232 per month if you worked between 7.5 and 10 years.
Medicare Part B has a standard monthly premium of $134 in 2018, for people who earn up to $85,000 a year ($170,000 for a married couple). The premiums are higher if your income exceeds that amount. But for most people receiving Social Security benefits, actual premiums are a little lower in 2018, averaging about $130/month, deducted from Social Security checks. Part B enrollees pay an annual deductible of $183 in 2018 (some enrollees have supplemental coverage that pays the Part B deductible though).
Most people who have Original Medicare also have some sort of supplemental coverage, either from an employer or retiree plan or Medicaid, or from privately purchased Medicare Part D plans and/or Medigap plans. If you purchase supplemental coverage, the premiums will be in addition to the Part B premiums (and if applicable, the Part A premiums).