Medicare Part B premium

page 21 of the 2009 medicare & You book states, most people will pay the standard premium amount. However, your monthly premium will be higher if you meet the following conditions:
* You are single (file an individual tax return), and your yearly modified adjusted gross income is more than $82,000 (in 2008).
*You are married (file an joint tax return) and your yearly modified adjusted gross income is more than $164,000 (in 2008).
In both of the above examples the book refers to income in 2008 however the letters being sent to higher income people shows the income-related monthly adjustment amount based on your 2007 income tax return.