About 80% of their designated cost for a particular visit or procedure. Getting a doc to accept will become more difficult with time. Then, you will need the prescription add on of some kind. Then, you will need a supplement to cover some or all of the 20% Medicare leaves off.
The basic cost, now $98/person/month will balloon to, I believe, $247 by 2014. The exact costs can be found on the internet...just google Medicare and it should give you the sites with more detail.
Once you see what they do to doctor’s office payments, you will understand why the very good ones tend to shy away from accepting patients with Medicare. We had one essential to life doc who opted out of Medicare coverage around 2008. That left us with paying the 80% with the supplement paying PART of the remaining 20%.
And, Palin was right about Death Panels...alas.
Unless they have a supplement!!