The Centers for Medicare and Medicaid Services (CMS) updates the Part B premium each year. These adjustments are made according to formulas set by statute. By law, the monthly Part B premium must be sufficient to cover 25 percent of the program’s costs, including the costs of maintaining a reserve against unexpected spending increases. The federal government pays the remaining 75 percent.
Below are the annual Part B premium amounts from Calendar Year (CY) 1996 to 2006. For these years, and years prior to 1996, the Part B premium is a single established rate for all beneficiaries.
Year      Part B Premium     
1996     $42.50    
1997     $43.80    
1998     $43.80    
1999     $45.50    
2000     $45.50      
2001     $50.00   
2002     $54.00   
2003     $58.70   
2004     $66.60   
2005     $78.20   
2006     $88.50     
Beginning on January 1, 2007, the Part B premium is based on the income of the beneficiary.