They come for health care. They leave ready to vote.

“Something in that moment clicked,” said Martin, now an emergency room physician at Massachusetts General Hospital. From that seminal encounter, Martin hatched the idea for Vot-ER.

The organization helps patients register to vote — or receive information about voting —as they’re visiting a hospital or clinic.

Formally launched in the MGH emergency room in 2019, the nonpartisan initiative has expanded to more than 700 sites nationally, including 32 in Massachusetts, and spans community health centers, physician’s offices, medical schools, and emergency departments.

The non-profit is founded on the belief that encouraging patients to engage in the political process helps them improve the many factors that influence their health, including air quality, housing opportunities and access to healthy food.

The process starts with a simple conversation: a healthcare worker asks a patient if they are registered to vote.

“No one has asked me that before,” the young mother said to Martin on that cold February night.

All told, Vot-ER has helped 66,000 eligible voters register or sign-up for vote-by-mail ballots, including 4,500 in Massachusetts since 2019.

Participating sites and healthcare workers receive a bright blue lanyard and a badge to hang with their typical photo ID. Down one side of the Vot-ER badge, in bold red and white letters, is the question, “Ready to Vote?”

The badge also includes a QR code patients can scan with their cellphone and numbers they can text to receive a link to the Vot-ER site, which appears in English and Spanish. The site walks people through the process of registering to vote, allows them to check their registration status, request a mail-in ballot, or access more voting information in their own state. It also includes a helpline.

“I started to make the connection between the folks who are coming in to the ER to get care that is not emergency care, like coming in for … a prescription or for a place to sleep tonight,” Martin said.

“Demographically speaking, the people who are coming to the ER for these non- emergent presentations overlap almost uniformly with who is not registered to vote in this country,” he found.

The latest Census data from 2020 show that more than one in four Americans 18 and older are not registered to vote. And a Kaiser Family Foundation analysis of Census data reflects the gaping disparities Martin has witnessed in talking to patients: In Massachusetts, just 42 percent of Black residents of voting age are registered to vote, a rate among the lowest in the nation. Similarly, just 57 percent of Asian and 60 percent of Hispanic voting age residents are registered, both below national averages, the data show. By comparison, 77 percent of White voting age residents are registered in Massachusetts, above the national average.

Increasingly, research is finding that a person’s living conditions, known as their social determinants of health, can be as important as the health care they receive, said Heather Pierce,senior director of science policy at the Association of American Medical Colleges. The AAMC is collaborating with Vot-ER to boost civic engagement.

A recent survey by the organization found that Black people, who have often been marginalized in health care, are more likely to trust a hospital if it engages in voter registration services.

Yet the importance of such civic engagement is not routinely taught in medical school, said Senila Yasmin a second year Tufts University School of Medicine student. Yasmin led a voter registration drive with Vot-ER this fall and helped the school finish 8th highest in the nation among medical schools for new registrations and requests for mail-in ballots, according to Vot-ER.

“These are the students who in the future will be asking their patients about registration,” Yasmin said. “We need to make these conversations more normal in medical school.”

Greater Lawrence Family Health Center in August joined the Vot-ER initiative, distributing posters and “Ready to Vote” badges with the QR codes to workers at its 10 clinics and sites across Lawrence, Methuen, and Haverhill.

“Before this, we just put out the voter registration forms from the Secretary of State’s office,” said Mary Lyman, the center’s director of community relations. “The badge is quick and it’s easy and you are not killing a tree.”

Health care workers say they realize not everyone who they help register will follow through and vote. Martin, the Vot-ER founder, did not stay in touch with the young mother from 2018 who inspired the voting initiative.

But he remembers another young woman in her 20s whom he treated for an asthma attack last year. After she was stabilized and he was getting ready to send her home with a prescription, she asked about his Vot-ER badge. He explained how registering and voting helps to get her voice heard on important issues

“The patient looks at me, and she’s like, ‘No, I’m good,’” Martin said.

Normally, Martin is too busy in the ER to have extended conversations about voting with patients. But this day was different. He sat back down and explained to her that asthma rates in East Boston where she lived near Logan Airport were among the highest in the city because air pollution rates were also among the highest.

“I can help you with this asthma right now,” Martin told his patient. “But I can’t take the smog out of the air. So that’s up to you. And the only way that we’re going to help solve that is by you getting involved, and in making your voice heard.”

The woman took out her phone, scanned the QR code on his badge, and said, “OK, doc, I get it.”

Martin doesn’t know if she followed through and completed her registration process. But he counts that encounter as a victory.

“The goal,” he said, “is to have the patient one step closer to understanding this connection, that their civic health and their physical health are inextricably linked.”

Kay Lazar can be reached at kay.lazar@globe.com Follow her on Twitter @GlobeKayLazar.