HB 1920 directs the Texas Health and Human Services Commission to expand Medicaid eligibility to individuals diagnosed with specific mental health disorders, including bipolar disorder, dysthymia, schizophrenia, and severe chronic depression. Eligibility is limited to individuals with family incomes not exceeding 133% of the federal poverty level who apply for assistance and for whom federal matching funds are available. The bill requires the adoption of necessary implementation rules and permits a delay in implementation pending federal waivers or authorizations.