A crowd of doctors, nurses, and other health care advocates gathered on the steps of the Massachusetts State House on Saturday afternoon to call for a single-payer health care system to improve access to coverage.

The Rally to Take Back Health was one of several organized by health care groups as part of the National Day of Action for Improved Medicare for All.

Single payer health care — which is not part of the Affordable Care Act — would make health insurance a public service, as it is in other countries.

“I can tell you that in many countries, health care is a right,’’ Dr. Joia Mukherjee, chief medical officer at the nonprofit Partners in Health, said speaking through a microphone to the crowd of about 100 people. “In Rwanda, health care is a right. In Costa Rica, health care is a right. ... Part of our rights as human beings to exist is health care,’’ she said, to applause and cheers.

Protesters waved signs stating “Single-payer now,’’ “For-profit health care kills,’’ and “Health care for people not profits.’’ Passing motorists waved and honked horns in support. People were urged to sign petitions, calling for Democratic Senators Elizabeth Warren and Edward Markey to fight to create a single-payer health care system.

Ann Eldridge Malone, 54, a nurse on the faculty at the University of Massachusetts Boston, said she believes the health care system needs fundamental reform. She has worked for 20 years in a variety of settings, including an oncology unit, as a visiting nurse, and with homeless programs.

“I’ve seen in every one of those sessions, people suffering from diseases that could have and should have been identified much sooner,’’ Malone said.

Olivia Arnold can be reached at olivia.arnold@globe.com. Follow her on Twitter @olivia_arnold12