Count Us In (formerly known as the One Night Count) is the annual Point-in-Time (PIT) Count of individuals, youth, and families experiencing homelessness in Seattle/King County, Washington. For the 2017 count, All Home, the organization tasked with conducting Count Us In, implemented improved data collection methods for obtaining comprehensive, accurate, and actionable data. Methodology changes include: 1) countywide participation of paid guides and surveyors who were individuals with current or recent lived experience with homelessness engaged in the data collection process; 2) a shift from a known areas approach to a canvassing of census tracts in King County; 3) a sample-based qualitative survey including shelter and service locations, as well as street locations; and 4) the incorporation of a youth and young adult count component focused on unaccompanied youth and young adults under 25 years, previously conducted separately. On the night of the 2017 PIT Count, there were 11,643 people experiencing homelessness. Forty-seven percent of this population was unsheltered, living on the street, in parks, encampments, vehicles, or other places. An estimated 2,833 individuals were in families with children and 1,498 individuals were unaccompanied youth and young adults. More than three-quarters of unaccompanied youth and young adults were unsheltered.