Prior to Medicare Modernization Act in the year 2003, every person paid the same amount when it came to Medicare coverage. However, at the start of 2007, the US Congress allowed Medicare to charge retirees with high income higher premiums.

During 2009, for Part B Medicare, majority of the retirees paid $96.40 per month as premium. This amounted to 25 percent of the total cost, with the government funding the remaining 75 percent. However, if the retiree’s income was more than $85,000 as a single filer or $170,000 as a joint or married filer, then he or she ended up paying more. For individual retirees with income more than $213,000 as single filers and $426,000 as married or joint filers, the monthly premium was around $308.30. This basically meant that the retiree was paying 80 percent of the total cost, while the government was paying for the remaining 20 percent.

When trying to figure out how much a retiree would have to pay monthly as premium for Medicare Part B, the Social Security first checks the tax returns the person filed for the previous year. A person does not have to submit any document to the Social Security Administration to determine the premium. This is only to be done if the person has a major change in his or her income compared to the previous year on account of death, divorce, retirement or any other major circumstance. You will have to furnish the necessary documents to support your claim. Once the Social Security get the proof about the change in income, it will recalculate your monthly premium and the same has to be paid.