H omeless and vulnerably housed populations are heterogeneous 1 and continue to grow in numbers in urban and rural settings as forces of urbanization collide with gentrification and austerity policies. 2 Collectively, they face dangerous living conditions and marginalization within health care systems. 3 However, providers can improve the health of people who are homeless or vulnerably housed, most powerfully by following evidence-based initial steps, and working with communities and adopting anti-oppressive practices. 1,4,5 Broadly speaking, "homelessness" encompasses all individuals without stable, permanent and acceptable housing, or lacking the immediate prospect, means and ability of acquiring it. 6 Under such conditions, individuals and families face intersecting social, mental and physical health risks that significantly increase morbidity and mortality. 7,8 For example, people who are homeless and vulnerably housed experience a significantly higher prevalence of trauma, mental health conditions and substance use disorders than the general population. 7,9 Canadian research reports that people who experience homelessness face life expectancies as low as 42 years for men and 52 years for women. 7 A generation ago, homeless Canadians were largely middleaged, single men in large urban settings. 10 Today, the epidemiology has shifted to include higher proportions of women, youth, Indigenous people (Box 1), immigrants, older adults and people from rural communities. 13,14 For example, family homelessness (and therefore homelessness among dependent children and youth) is a substantial, yet hidden, part of the crisis. 15 In 2014, of the estimated 235 000 homeless people in Canada, 27.3% were women, 18.7% were youth, 6% were recent immigrants or migrants, and a growing number were veterans and seniors. 10