Legislative language has yet to be released, but press reports have indicated the outlines of a potential agreement between House Speaker John Boehner and Minority Leader Nancy Pelosi. The proposal is expected to permanently repeal the sustainable growth rate (SGR) mechanism established in 1997 for setting physician payments and overall physician spending within Medicare. After only a few years, spending began to exceed the SGR spending targets, prompting Congress to pass a series of bills—known as the “doc fix”–adjusting the targets upward for short periods.

In general, Congress financed these short-term doc fixes by reducing spending elsewhere in the budget. More than $165 billion worth was covered this way. But lawmakers used two statutory mechanisms to lower the cost of these short-term spending bumps and promised to recover the remaining costs in the future. Each time it has come up, Congress has kicked the proverbial can down the line.

When it comes to physician payment, the agreement being negotiated by the congressional leaders is expected to do two things: First, it would fill in the shortfall from repeated budgetary gimmicks. Maintaining flat payment rates for the future, rather than letting the SGR cuts take effect, would cost $137.4 billion, according to the Congressional Budget Office. This would not be paid for but would be absorbed into the deficit. The second part of the agreement, which provides for modest increases in physician payments in the coming years, would have a net cost of $37.1 billion, according to CBO. This increase in spending would be paid for.

One ramification of the proposed $137 billion increase in deficit spending: Seniors would fund a significant portion. As CBO noted in its 2009 score of an earlier, unsuccessful SGR repeal bill: “Beneficiaries enrolled in Part B of Medicare pay premiums that offset about 25 percent of the costs of those benefits. . . . Therefore, about one-quarter of the increase in Medicare spending would be offset by changes in those premium receipts.”

The House Republican leadership is well aware of the premium effects of an unpaid-for SGR repeal. When then-Speaker Pelosi brought an unpaid-for SGR repeal bill to the House floor in November 2009, then-Minority Leader Boehner called it an “absolute train wreck,” because it “forces seniors to pay higher premiums.” All but one House Republican voted against the legislation—largely because it did not include spending cuts to pay for the repeal.

It remains unclear how many House Republicans today might change their position from 2009, or what their public justification for doing so would be. What is clear is that any unpaid-for legislation would have a fiscal impact on America’s seniors as well as the federal budget.

This post was originally published at the Wall Street Journal Think Tank blog.