Williams’s recent match was the first one she has played this year. The only woman older than she is now to win a tour-level singles match was Martina Navratilova, whose last triumph came in 2004 at age 47. Williams was once the No. 1 ranked women’s payer in the world and has made $42.6 million playing professional tennis.

Champion tennis player Venus Williams says she’s coming out of retirement because she needs health insurance, but industry experts say her example shows how little Americans understand their health care options.