HB 4121 strengthens Medicaid and Child Health Plan Program (CHIP) eligibility determinations for juveniles committed, placed, or detained in state facilities. It requires HHSC, the Texas Juvenile Justice Department, and the Department of Family and Protective Services to coordinate efforts to assess and enroll eligible individuals in these programs before their release. The bill mandates that the Texas Juvenile Justice Department create a release plan to ensure continuity of care and submit annual reports detailing the number of juveniles enrolled and receiving services.