The announcement - by Nutter and Julián Castro, U.S. secretary of housing and urban development - comes about a year and a half after the mayor accepted a national challenge from President Obama to end veteran homelessness by the end of 2015. About 859 mayors, nine governors, and 166 county and city officials took the challenge.
According to HUD, veteran homelessness has decreased 33 percent nationally, and about 15 municipalities have reached the "functional zero" goal, including large cities such as Houston and smaller communities like Troy, N.Y.
Virginia declared it was at functional zero last month, on Veterans Day. Philadelphia officials had pledged to meet the same goal, but came in about five weeks behind.
Marie S. Nahikian, the city's director of supportive housing, said she believed that the city made the Veterans Day deadline, but that the federal government wanted to see more data and further assess the system Philadelphia put in place before making the designation.
Nahikian said homeless veterans in Philadelphia are placed in emergency housing in a few days on average, in transitional housing in 47 days, and in permanent housing in 105 days.
Castro on Wednesday called on the city to help other municipalities "as they reach for that finish line," and to apply the lessons learned in this project to ending homelessness. City officials said there are about 600 chronically homeless people in Philadelphia.
"You have actually done it. You have effectively ended veteran homelessness," Castro said. "The thing is that we can't stop our work until every single veteran has a place to call home in the United States. That means that you have a role to play in teaching other communities how you did it."
Nutter said the project was carried out by a coalition, known as PhillyVets Home, that includes nonprofit organizations, the Philadelphia Housing Authority, and the Cpl. Michael J. Crescenz VA Medical Center in University City.
He said the system includes a single point of entry for veterans, a streamlined process to determine eligibility through the VA, immediate transitional housing for up to 50 veterans, and an immediate permanent housing plan.
Sister Mary Scullion, executive director of Project HOME, said the success in Philadelphia was due as much to the federal government as to local stakeholders. She said the Obama administration had dedicated huge financial resources to ending veteran homelessness. Implementation falls on the local agencies, she said.
"I think the key has been the federal commitment," she said.
Scullion said it can take years of being offered help before a homeless person is ready to take it: "It just takes time to reach the people, to build that relationship of trust, and then to have the most appropriate place for them to come in."
Debra Devine, a mother of five and a former specialist in the Army, said she had experienced more than a decade of homelessness when, during a routine visit to the VA Medical Center last summer, someone suggested she stop by the facility's housing office.
Devine was told she was eligible for a federal voucher to pay for permanent housing. Last Dec. 22, she, her son, her fiance, and his daughter moved into their home.
"My kids . . . they went into the house, they was doing flips, they was kissing the walls," she said. "They were so happy."