; or a hospital labor and delivery model and planned home birth model. (c) Interdisciplinary providers Each Center for Excellence on Optimal Maternity Outcomes shall include the following interdisciplinary providers of maternity care: (1) Obstetrician-gynecologists. (2) At least two of the following providers: (A) Family practice physicians. (B) Nurse practitioners. (C) Physician assistants. (D) Certified professional midwives. (d) Services Research conducted by each Center for Excellence on Optimal Maternity Outcomes shall include at least 2 (and preferably more) of the following supportive provider services: (1) Mental health. (2) Doula labor support. (3) Nutrition education. (4) Childbirth education. (5) Social work. (6) Physical therapy or occupation therapy. (7) Substance abuse services. (8) Home visiting. (e) Coordination The programs of research at each of the two Centers of Excellence on Optimal Maternity Outcomes shall compliment and not replicate the work of the other. (f) Authorization of appropriations There is authorized to be appropriated to carry out this section $2,000,000 for each of the fiscal years 2019 through 2023. 520. Expanding models allowed to be tested by Center for Medicare & Medicaid Innovation to include maternity care models Section 1115A(b)(2)(B) of the Social Security Act ( 42 U.S.C. 1315a(b)(2)(B) ) is amended by adding at the end the following new clause: (xxv) Promoting evidence-based models of care that have been associated with reductions in maternal and infant health disparities, including incorporating the use of doula and promotoras support for pregnant and childbearing individuals into evidence-based models of prenatal care, labor and delivery, and postpartum care, and supporting the appropriate use of out-of-hospital birth models, including births at home and in freestanding birth centers. . 521. Development of interprofessional maternity care educational models and tools (a) In general Not later than 6 months after the date of the enactment of this Act, the Secretary of