Fifteen years ago, Carl Siciliano founded the Ali Forney Center, now the largest U.S. housing program for homeless LGBT youth. The New York City–based organization is named after the late advocate Ali He’shun Forney. He was shot in Harlem in 1997. His killing has never been solved.

The facility—which includes a 24-hour drop-in center, a medical clinic, a mental health clinic and substance abuse and job training programs—has evolved into a model for youth housing. The center also provides short-term shelter and longer-term housing for LGBT youth ages 13 to 24—it’s one of the few organizations nationwide that do so. About half of the center’s clients come from the New York metropolitan area; the rest come from across the country.

Siciliano is HIV negative, but he has worked with HIV-positive people in New York since 1987, the year he came out as gay. He was volunteering with homeless people and engaging in nonviolent resistance to the Reagan administration.

He later worked as a home attendant for a man with AIDS. Soon after, Siciliano started working as a case manager for formerly homeless people—Siciliano estimates that 20 percent of them had HIV. After that, he worked at Safe Space, which opened up the first residential program for HIV-positive teenagers.

“One of my deepest frustrations with public policy for HIV is that there’s just not enough responsiveness to youth homelessness,” says Siciliano, citing conservative federal estimates that there are more than 500,000 homeless youth across the country and that 40 percent of them are LGBT. Sadly, there are only 450 beds designated for LGBT youth nationwide. The center has more than 200 kids on its waiting list.

What happens to these kids while they’re waiting? “They’re often forced into sex work,” Siciliano says. “When you’re desperate about making it through the night, you’re not prioritizing what could happen to you years down the road.” Fortunately, thanks to its efforts, the center has seen a big decline in HIV cases.

In 2013, the center got the city to increase the available beds by nearly 400 over the next few years. And this spring, the group is opening an 18-bed long-term transitional home in Manhattan’s East Village called the Bea Arthur Residence, which Siciliano had sought to open for years.

In fact, the Ali Forney Center has been so impactful that in 2012, Siciliano was honored by the White House as a Champion of Change in the fight against youth homelessness.

“I’m anticipating that we’re going to lose over a million dollars in funding,” says Siciliano about his thoughts on the Trump administration. “In the absence of governmental support, the broader LGBT community and our allies need to start creating structures to protect LGBT youth.”