Mike Gavitt sits on the edge of an unmade twin bed in a small, nondescript house off Forest Avenue in Portland and lights a cigarette.

Most of what he owns is stuffed into a duffel bag on the floor: a worn pair of corduroys, socks and underwear, a small American flag stapled to a stick. His U.S. Marine Corps cap is within arm’s reach on a nearby bureau.

Gavitt, 70, moved into this room in a sober living house at the beginning of November. Before that, he was sleeping on a cot at the city’s Oxford Street Shelter.

“I was really exhausted there,” Gavitt says in a gravelly voice. “World weary, I like to call it. I’m glad they got me a place.”

He got a place because he’s a veteran, and veterans staying at the shelter get priority when it comes to housing.

But Gavitt is also among another segment of the homeless population that the staff at Oxford Street is now prioritizing for housing and support services: those who teeter on the brink of becoming chronically homeless.

“We’re trying to identify the people who are extremely vulnerable,” says shelter director Rob Parritt.

The number of homeless people in Maine fell by 9.6 percent from 2013 to 2014, according to the U.S. Department of Housing and Urban Development. But the homeless population here – 2,726 people, according to HUD’s recent survey – is still larger than it was in 2010, and the city of Portland is exploring the idea of building a larger shelter and focusing on efforts to move people into permanent housing more quickly.

By his own account, Gavitt has come close to joining the ranks of the chronically homeless – those who’ve been homeless for at least a year or have had four episodes of homelessness in three years – for much of his adult life. That fact might surprise anyone who knew him growing up, but it doesn’t surprise Parritt.

“It doesn’t matter who your family is,” he says. “Homelessness can happen to anybody. If you have enough issues, your level of affluence doesn’t matter.”

Gavitt was raised in Peterborough, New Hampshire, in what he describes as a comfortable middle-class family.

“Great parents. Great childhood,” Gavitt says. “I was an athlete, president of my senior class.”

But it was his big brother, Dave, who was the family hero. A star on the basketball court at Dartmouth College, Dave Gavitt – who died three years ago – went on to help found the Big East Conference and was a vice president of the Boston Celtics.

Mike Gavitt’s life took a different direction. He dropped out of college, joined the Marines in 1965 and spent 14 months in Vietnam. When he came home he couldn’t seem to find his footing.

He married and divorced, twice. His only child was raised by his ex-wife in Saco.

Gavitt says he was diagnosed with bipolar disorder in his 40s, and for many years he drank. The drinking stopped a long time ago, he says, thanks to Alcoholics Anonymous. But he still wasn’t able to settle down. Instead, he drifted.

“Usually I was working, but sometimes when you’re traveling and can’t get a job right away, the money runs out.”

And when it did, he’d head to the nearest shelter.

“Spent a lot of time in shelters,” he says. “Salt Lake City. Florida.”

In later years, despite a pension from the VA, Social Security and help from his family, he continued to struggle to keep a roof over his head.

“I got behind. You gotta come up with first, last and security. Damn impossible.”

He had one long stretch off the street – almost 15 years in public housing in South Dakota. That ended two years ago.

“I don’t know what happened,” he says. “Stopped taking my medication, is one thing.”

For now, he has a place to call home. Given his tendency to roam, though, there’s no guarantee he’ll stay. He’s talked about heading south, or going to Rhode Island, where he still has some family.

But even a short stint in housing is a step in the right direction for someone who has been on and off the street as often as Gavitt has.

“We like to say in our line of work that that may be six months or a year where a person is not at risk of dying on the streets,” Parritt says. “And next time they’re housed, that may be the hook, that may be the stopping point.”

Maybe it will be the stopping point for Mike Gavitt, maybe it won’t. Whatever the future holds he’ll face it without regret. Gavitt says the days of looking at how his life turned out and feeling sorry for himself are long gone.

“I don’t think like that anymore,” Gavitt says.

“I’m grateful for what I got. AA taught me that … there’s always something to be grateful for.”