The Families Care Act amends the Older Americans Act to expand support available to family caregivers under the National Family Caregiver Support Program. The bill adds peer support services to the types of assistance the program can provide, alongside existing services like individual counseling. States are also required to consider the unique needs of caregivers whose families have been affected by substance use disorder or opioid addiction when delivering these services. Additionally, the bill requires the federal government to regularly publish and share information about the program on an ongoing basis rather than on a set schedule. The legislation affects family caregivers, older Americans, and their families, particularly those dealing with substance use issues, by ensuring their support needs are recognized and addressed.