A bipartisan measure to permanently solve one of the most nettlesome issues in the nation's health care system could be ready for release as early as Thursday, Fox News has learned.

Lawmakers are crafting permanent "doc-fix" legislation that would create a "patch" to prevent doctors who treat Medicare patients from seeing steep cuts to their reimbursement payments.

The issue at hand is the Sustainable Growth Rate, the special payment the federal government reimburses to doctors who treat Medicare patients. Without a patch, physicians would see a 24-percent decrease in their pay this year and millions of Medicare patients could see their health care choices limited.

Lawmakers have been under pressure has been on to craft an agreement before Senate Finance Committee Chairman Max Baucus, D-Mont., leaves the Senate to become U.S. ambassador to China. The Senate is expected to confirm Baucus' nomination on Thursday.

In December, the Senate Finance Committee and the House Ways and Means Committee passed separate legislation that would repeal the Sustainable Growth Rate formula and replace it with a new system to pay doctors who treat Medicare patients.

Fox News has learned the bipartisan measure being crafted would increase the premiums patients pay by half a percentage point. The formula would cost about $121 billion over the next decade. The proposal does not address how the fix will be funded.

The bill is being crafted by Baucus, House Energy and Commerce Committee Chairman Fred Upton, R-Mich., and Rep. Henry Waxman, D-Calif., the top Democrat on that panel, among other lawmakers.

“These negotiations are never easy, but we fought hard to develop the strongest, most effective policy to protect seniors' access to their doctors, and I'm pleased we have a bipartisan agreement," Upton told Fox News. "There is still much work left to do but I look forward to building on this milestone."

Fox News' Chad Pergram contributed to this report.