In the Homeless SDOH demo we consider the challenges of John Thomson, who is now homeless in NYC. This Chronically Homeless/Housing Insecurity demo involves a Shelter Management app, a Homeless Management Information System and a Case Management Referral System. The shelter management app uses a HUD HMIS standard API over HTTPS. The Case Management Referral System uses a publish and subscribe API similar to the FHIR Subscription service to learn of John’s housing insecurity issues, and then could use FHIR or 360X electronic referral standards, or a simple electronic fax or print and post to get a referral for housing to the appropriate community based organization or agency.