Currently unemployed, Ms. Whitaker is nervous that in two years she will again find herself without health coverage. She and Mr. Jamieson, who have been together five years, said they would marry if necessary so he could insure her under the group policy provided by his employer, the drug manufacturer Pfizer. But nothing is guaranteed.

“If Joe were ever to lose his job or medical coverage, I do feel it would be possible for me to find myself without insurance again,” said Ms. Whitaker, who reads lips to compensate for her hearing loss. “I’m extremely nervous about whether I’m going to be able to afford my medications once my coverage runs out.”

Bills have been introduced in Congress since 2000 to lift the 36-month limit and extend coverage of immunosuppressant drugs indefinitely. They have never made it to a vote, largely because of the projected upfront cost; the Congressional Budget Office estimates that unlimited coverage would add $100 million a year to the $23 billion Medicare kidney program.

But the cost-benefit analysis would seem obvious. The most recent report from the United States Renal Data System found that Medicare spends an average of $17,000 a year on care for kidney transplant recipients, most of it for anti-rejection drugs. That compares with $71,000 a year for dialysis patients and $106,000 for a transplant (including the first year of monitoring).

“It doesn’t make any sense at all,” Ms. Whitaker said. “Somebody’s not looking at the numbers.”

A provision to cover the drugs is in the sweeping House health care bill, which has cleared three committees. It is uncertain whether the Senate Finance Committee will include it in its bill.

Since 1973, end-stage renal disease has been the only condition specifically covered by Medicare regardless of age. In 1988, coverage was extended for 12 months to anti-rejection drugs, which had recently been developed. Congress gradually lengthened the cutoff to 36 months, and then in 2000 made the benefit unlimited for those who are at least 65 or disabled. The rationale for leaving out younger transplant recipients was simply that the money was not there, Congressional aides said.

Ms. Whitaker was married when her Medicare eligibility expired after her first transplant, and her husband was able to insure her under his group policy. They divorced in 2001, and she became uninsured until taking a job at Kinko’s that provided health benefits.