As expected for more than a week, President Obama signed into law Wednesday evening a one-year freeze on 25 percent Medicare payments to doctors. The cuts were due to kick in Jan. 1.

The legislation, passed last week by the Senate and earlier this month by the House, is meant to give politicians time to hammer out a permanent solution to the cuts.

The cuts come about from the so-called sustainable growth rate formula, born of a 1990s law requiring Medicare payments to be in line with national growth. It's estimated a permanent fix could cost more than $200 billion over the next decade.

"We all agree that this formula needs to be changed," wrote Nancy-Ann DeParle, a health reform official, on the White House blog Wednesday. "Now's the time to get it done."

The White House credited the largely bipartisan bill's passage to activism by seniors and doctors groups, such as the American Medical Association and AARP.

The fully paid-for $19.2 billion bill is offset by raising overpayment penalties for consumers who will get tax subsidies to buy health insurance from state-run exchanges, starting in 2014.

The bipartisan bill also repeals a delay in implementing a new Medicare payment structure for nursing homes, and extends the therapy caps exception process through next year.