Since 2008, Pathways has increased from 125 to about 300 the number of people it serves, said Christine Simirglia, executive director of Pathways' West Philadelphia office.
Funding comes from a variety of federal sources, channeled through city offices that work with the homeless and individuals with behavioral health issues.
Pathways has apartments across the city that it leases for clients. It asks them to contribute a third of their government benefits toward rent, using federal funds to cover the rest. Caseworkers then connect them to addiction-recovery services or mental-health treatment.
Simirglia said about 90 percent of those placed by Pathways stay with the program and retain their housing.
"If you deal with the anxiety of homelessness and allow people to feel safe and have food to eat," she said, "then they're going to be more apt" to deal with their addictions or mental illness.
To maintain someone in the Pathways program costs $28,000 a year.
A recent evaluation of Pathways, conducted by Fairmount Ventures Inc., a consultant to nonprofits, found that the agency saves the city money by reducing the use of emergency services by chronically homeless individuals.
Contact staff writer Jennifer Lin at 215-854-5659, email@example.com or @j_linq on Twitter.