The D.C. Open will not be a one-stop hello-and-farewell appearance for 45-year-old Venus Williams. She had been away from the tour for 16 months before showing up in Washington this week and winning once each in singles and doubles.

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.

I had to come back for the insurance,” Williams, 45, said this week after beating Peyton Stearns — 22 years her junior — at the Mubadala Citi DC Open in Washington, D.C. “They informed me this year that I’m on COBRA,