Medicaid Services Investment and Accountability Act of 2019 This bill alters several Medicaid programs and funding provisions. (Sec. 2) The bill temporarily extends the applicability of Medicaid eligibility criteria that protect against spousal impoverishment for recipients of home- and community-based services. (Sec. 3) The bill also establishes a state Medicaid option to provide for medical assistance with respect to coordinated care provided through a health home (i.e., a designated provider or team of health-care professionals) for children with medically complex conditions. States must determine payment methodologies in accordance with specified requirements; payments also temporarily qualify for an enhanced federal matching rate. (Sec. 4) The bill also temporarily extends the Medicaid demonstration program for certified community behavioral health clinics. (Sec. 5) The bill increases funding available to the Money Follows the Person Rebalancing Demonstration Program. (Under this program, the Centers for Medicare & Medicaid Services may award grants to state Medicaid programs to assist states in increasing the use of home and community care for long-term care and decreasing the use of institutional care.) (Sec. 6) Further, drug manufacturers with Medicaid rebate agreements for covered outpatient drugs must disclose drug product information. Manufacturers are subject to civil penalties for knowingly misclassifying drugs. Manufacturers are also required to compensate for rebates that were initially underpaid as a result of misclassification (whether or not such misclassification was committed knowingly).