You'd pay monthly premiums plus an additional amount, which is based on what you report to the IRS. Because individual plan premiums vary, the law specifies that the amount is determined using a base premium.
And regarding the premiums, what if you determine I was a higher-income beneficiary?
You'd pay a larger percentage of the total cost of Part B based on the income you normally report to the Internal Revenue Service IRS. You'd pay monthly Part B premiums equal to 35, 50, 65, 80, or 85 percent of the total cost, depending on what you report to the IRS.