Programs that are staffed by outreach workers who spend time with people who live on the street, build relationships with them, identify and address their immediate needs (e.g., crisis intervention, food, clean clothing, hygiene kits, blankets, someone to listen) and provide information about and linkage to longer-term forms of support such as shelter, counseling, drug and alcohol detoxification and rehabilitation, care/case management and, where applicable, family reunification services. Street outreach programs may be staffed by volunteers or peers who were formerly homeless; and may target special populations such as homeless youth at risk for sexual abuse or exploitation, veterans, or people with specific medical or mental health conditions, or be available to the larger homeless population.

Programs that provide structured therapy groups or other interventions which help recovering drug and/or excessive alcohol users make the cognitive, behavioral and attitudinal changes that are necessary to prevent them from returning to their previous patterns of use. The program helps participants deal in a very focused way with a wide variety of issues that have an impact on their commitment to sobriety and may include topics like exercise, nutrition, boredom, addictive behavior, looking forward, work and recovery, guilt and shame, the role of 12-step programs, staying busy, truthfulness, trust, repairing relationships, anger management, money management and dealing with feelings.

Programs based on a harm reduction model that provide a safe and supportive environment which allows individuals who use drugs and/or alcohol to drop in and access multiple related services including group and individual counseling, day beds, showers, clothing, medical care, needle exchanges, sterile injection equipment and overdose prevention training, as well as information and referral, social activities and snacks. The programs may be structured for specific populations such as women or sex trade workers or be open to all.

Programs whose commitment to reducing the harmful consequences of risky and sometimes illegal behaviors (such as recreational drug use and sex work) as opposed to adopting a "zero tolerance" approach, influences the types of services they offer and/or the way their services are delivered.

Individuals and families who have no fixed, regular and adequate residence, who are residing temporarily with relatives or friends or who live on the street, in emergency or transitional shelters, in a hotel or motel paid for with a shelter voucher, in seriously substandard housing or in an abandoned building, place of business, car or other vehicle, or other public or private place that is not ordinarily used as a regular sleeping accommodation for people. Some people who are homeless have issues with substance abuse, chronic or severe mental illness, chronic unemployment or underemployment, or other problems that prevent them from obtaining housing.

Programs that provide information and/or services that deal with the topic of homelessness.