Runaway and Homeless Youth and Trafficking Prevention Act of 2019 This bill modifies and reauthorizes through FY2025 the Runaway and Homeless Youth Act, which provides community-based services for runaway or homeless youth who are in need of temporary shelter, counseling, or aftercare services. Specifically, the bill makes grants for centers and services for five-year terms and such grants must include trauma-informed and culturally-competent services, as appropriate. Grant recipients must make services accessible to runaway or homeless youth who are victims of sexual abuse, exploitation, or trafficking. Grant recipients also must collect, and keep confidential, specified aggregated data about the demographics of program participants. The bill requires grants for home-based services to (1) include suicide prevention, (2) provide staff training about trauma-informed care, and (3) ensure eligibility for youth at risk of separation from their family. The bill also revises and expands the transition living grants program to provide five-year grants to support long-term residential services for older homeless youth. Additionally, the bill requires the Department of Health and Human Services (HHS) to coordinate with specified agencies to deliver programs for runaway and homeless youth and provide five-year grants for technical assistance to regional nonprofit organizations to implement trauma-informed programs for such youth. Further, the bill authorizes five-year grants for the sexual abuse prevention program and the national communications system to connect runaway and homeless youth with their families and service providers. The bill also prioritizes grants for research and evaluation projects that examine the intersection of human trafficking and youth homelessness populations, among other provisions.