INDIANAPOLIS — Indiana doctors are joining a nationwide petition drive urging Congress to forestall a looming cut in Medicare reimbursements and to permanently revamp the payment formula so that doctors don't have to turn away potential patients who rely on the federal program.

Doctors who see Medicare patients are facing a 21.2 percent cut in reimbursements starting Wednesday under the current structure.

Lawmakers have put off the issue for a decade by temporarily delaying the changes, but now doctors say they want an overhaul of the payment formula that will shore up Medicare once and for all.

"Congress' constant toying on this issue and the inability to solve it threatens access to care for all our seniors and military families," said Dr. Frederick Ridge, president of the Indiana State Medical Association.

Indiana is joining several other states — Texas doctors launched their campaign, seeking 1 million signatures, on Monday — that are participating in the campaign.

Supporters can sign the petition online at ipetitions.com/petition/meltdown.

"We're asking Congress for a rational Medicare physician payment formula that keeps up automatically with the cost of running a practice," Ridge said.

"As physicians, we want to continue taking care of Medicare patients, and we can do that if Congress focuses on correcting this issue."

The slash in reimbursement rates dates to the budget that Congress passed in 1997, which ties Medicare funding to a formula called the sustainable growth rate. The intent was to ensure that Medicare spending did not spiral out of control.

That formula's trigger effect has mandated cuts in Medicare reimbursements every year. Since Congress consistently has passed stopgap measures, none of those cuts has materialized.

Still, doctors say that instead of counting on Congress to keep up the delays, they want a long-term solution.

Medicare spending last year amounted to $484 billion.