When Erika Royer’s lupus led to kidney failure four years ago, her father, Radburn, was able to give her an extraordinary gift: a kidney.

Ms. Royer, now 31, regained her kidney function, no longer needs dialysis and has been able to return to work. But because of his donation, her father, a physically active 53-year-old, has been unable to obtain private health insurance.

Like most other kidney donors, Mr. Royer, a retired teacher in Eveleth, Minn., was carefully screened and is in good health. But Blue Cross and Blue Shield of Minnesota rejected his application for coverage last year, as well as his appeals, on the grounds that he has chronic kidney disease, even though many people live with one kidney and his nephrologist testified that his kidney is healthy. Mr. Royer was also unable to purchase life insurance.