This guide is meant to help communities that want or need to do three different but related things: 1) calculate an expected number of homeless people over a year's time when you only have data from a point-in-time (PIT) count; 2) use both PIT information and projections to annual levels of homelessness to figure out how many chronically homeless people you are likely to have, now and in the future; and 3) plan and develop appropriate levels of permanent supportive housing to a) end long-term homelessness for people who currently are chronically homeless, b) end homelessness for people with special needs who are currently homeless and at risk of long-term homelessness, and c) prevent homelessness for people with special needs who are at high risk of homelessness if their housing and support needs are not met. (Authors)