In addition to that being potentially unfeasible, having supported himself his entire adult life he found the notion of asking a friend or relative to submit extensive financial documentation and co-sign a lease deeply unappealing.

“I never had to have a guarantor in my life,” said Mr. Donahue, who tried to placate landlords by telling them that in addition to the security deposit, he had renters’ insurance that would cover any potential damages to the apartment. “You don’t need someone with half a million dollars in a bank account.”

But it seemed that you did. With landlord after landlord turning him down and his time at the hostel drawing to an end — guests at the hostel were limited to stays of less than 30 days a year — he was left with one option: He contacted the city’s Department of Veterans’ Services, which offered him a bed in a veterans’ shelter.

“It was a pretty nice at the shelter, which was set up like apartments with individual rooms,” Mr. Donahue said. Working with the city agency, he was finally able to get a landlord to accept his income documentation for a $1,500-a-month studio in Flushing, Queens.

That the broker for the apartment, which he found on Craigslist, was also a veteran, helped too. The $1,000 bonus that the city offers landlords who rent to homeless veterans — an amount that has since been raised to $3,500 — was an added sweetener.