For a decade now, the formula that supposedly sets Medicare’s budget has returned results that fall far short of the program’s actual costs. So every year, Congress passes legislation to make up the difference — often after a drawn-out fight. Legislators work up through the Christmas holidays, doctor payments get delayed and patients get nervous. But without fail, a short-term doc-fix always passes. Then it runs out, a year or so later, and Washington goes through the same policy dance all over again.

It’s hard to find anyone in Washington who thinks this is the right way to handle health-care policy. Even so, it’s a funding fight that could soon become more frequent, as the health reform law lays the groundwork for an analogous doc-fix in the Medicaid program.

Right now, Medicaid pays doctors 34 percent less than Medicare, which, in turn, pays less than private insurance. Health policy experts worry that such low payment rates scare doctors away from the entitlement program, creating access issues for Medicaid patients.

The health reform law changes that: It raises Medicaid rates for primary care to match those of Medicare for 2013 and 2014. That, the Obama administration hopes, will lure doctors to accept Medicaid patients — and also prevent some costly emergency room visits down the line.

But there’s a problem: The payment boost runs out at the end of 2014. While the federal government estimates that it will spend $11 billion raising provider rates for 2013 and 2014, no additional federal funds are appropriated beyond that.

There’s already some thinking, among the health-care provider community, that a fierce lobbying battle could play out as doctors look to turn a short-term pay boost into a permanent one.

“We’re ready to lobby for what’s right to improve the situation,” says Roland Goertz, chair of the Academy of Family Physicians. “We’re ready to go to the mat for what works, and we need to be going in this direction.”

Primary care reimbursements are, in Goertz’s view, an issue worth fighting for — especially after gaining a foothold within the Affordable Care Act. “There’s little question that low reimbursement discourages doctors from caring for Medicaid patients,” he said. “Medicaid parity will enable doctors to care for more Medicaid patients.”

Differences certainly exist between Medicaid and Medicare funding. The former tends to have a stronger lobbying presence in Washington that is front-and-center in Medicare funding fights. Older Americans vote at higher levels, giving increased urgency to the Medicare doc-fix.

At the same time, Congress doesn’t usually like to come out against doctors: Their approval ratings are among the highest of any profession. And if groups like Goertz’s are ready to fight, Congress could be in for a double dose of doc-fix come 2014.