Advancing Care for Exceptional Kids Act of 2017 or the ACE Kids Act of 2017 This bill allows a state Medicaid program or child health plan to provide coordinated care through enhanced pediatric health homes (EPHHs) for children who have complex medical conditions. Pursuant to an agreement with a state, an EPHH offers: (1) comprehensive pediatric care management, (2) care coordination and health promotion, (3) comprehensive transitional care, (4) patient and family support, (5) referrals to community and social support services, (6) the use of health information technology to link services, and (7) coordination of access to the full range of pediatric specialty and subspecialty medical services. In general, an EPHH must enroll any eligible child who requests enrollment. A child who opts to enroll shall have the option to disenroll from the EPHH and instead receive covered services under the state Medicaid program or the Children's Health Insurance Program (CHIP). Each state shall develop a methodology for payment to EPHHs under the state plan. The bill establishes requirements related to data collection and quality assurance. The Centers for Medicare & Medicaid Services (CMS) shall issue guidance to states on best practices for ensuring that children with complex medical conditions receive prompt care from out-of-state providers when medically necessary. The Medicaid and CHIP Payment and Access Commission must report to Congress and the CMS on specified information related to children with complex medical conditions.