The three types of homelessness

Researchers and service providers usually divide homelessness into three categories based on duration and pattern. The categories matter because each type calls for a different kind of help.

Transitional homelessness (~80%)

The majority of people who experience homelessness are homeless once, briefly. They lose housing after a job loss, a medical event, a divorce, or a fight that ended a couch-surfing arrangement. They stay in a shelter, in a car, with relatives, or in some other improvised setup for a few weeks to a few months. Then they get back into housing and stay there.

These people are usually never counted in the popular image of "the homeless," because by the time the public sees them, they are housed again. But they make up roughly four out of five people who pass through the system in any given year.

What helps transitional homelessness: rapid rehousing (a short-term rent subsidy plus help finding a unit), emergency cash assistance, eviction prevention before the eviction happens.

Episodic homelessness (~10%)

About one in ten people experiencing homelessness cycle through it repeatedly. They get housed, lose housing, get housed again. This is usually associated with active substance use, untreated mental illness, or unstable employment. Each episode is relatively short, but the pattern repeats across years.

What helps episodic homelessness: supportive housing (a unit with case management attached), substance use treatment that doesn't require sobriety as a precondition for housing, mental-health treatment that is integrated with housing rather than separate from it.

Chronic homelessness (~10%)

A small minority are homeless for a year or longer, or have had four or more episodes of homelessness in the past three years and have a disabling condition (severe mental illness, physical disability, substance use disorder, or chronic medical condition).

This is the population most visible to the public — the people you see sleeping on streets, in encampments, in libraries during the day — and the population most often misunderstood. They are also the most expensive: the chronically homeless consume an outsized share of emergency-room visits, jail stays, and crisis services. Cities that have studied the cost have repeatedly found that housing a chronically homeless person costs less than leaving them on the street, because the savings on emergency services more than offset the cost of the housing.

What helps chronic homelessness: Housing First (permanent housing with no preconditions like sobriety or treatment compliance) plus voluntary, intensive case management. Approaches that require people to "get clean first" or "get well first" before being housed have failed in study after study.

Why the categories matter

If a city's homelessness strategy is designed around the chronic population — long, expensive, treatment-heavy programs — it will fail the transitional majority, who mostly just need a few months of rent help. If it is designed only for the transitional majority — short-term rent assistance only — it will fail the chronic minority, who need permanent supportive housing.

A well-designed system has all three: prevention and rapid rehousing for transitional cases, supportive housing for episodic cases, and Housing First with wraparound services for chronic cases.

Continue with Homelessness by population.