Transparent Drug Pricing Act of 2019 This bill establishes several requirements relating to the prices of prescription drugs. For example, state Medicaid drug-use review programs must require pharmacists to disclose an individual's out-of-pocket cost for a prescription drug, and the price without health insurance, at the point-of-sale. Additionally, health insurers must publish the co-payment amount for each covered prescription drug prior to the annual open-enrollment period. The bill also temporarily prohibits the retail list price of drugs and biologics from exceeding the lowest retail list price among Canada, France, the United Kingdom, Japan, or Germany.