Advancing Care for Exceptional Kids Act or the ACE Kids Act This bill amends title XIX (Medicaid) of the Social Security Act to establish 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. A state shall make payments for such health-home services regardless of whether they are provided through a fee-for-service or managed-care system. For an initial period of eight fiscal-year quarters, the federal matching rate applicable to such payments shall be increased by 20 percentage points, not to exceed 90%. A state that exercises this option shall specify its methodology for determining payment and evaluating quality of care, in accordance with requirements established by the bill. In addition, the state must meet specified requirements regarding hospital referrals, out-of-state providers, education and outreach, data collection, and reporting. The Centers for Medicare & Medicaid Services must issue guidance on best practices for using out-of-state providers to provide care to children with medically complex conditions. The Medicaid and Children's Health Insurance Program (CHIP) Payment and Access Commission must report to Congress and to the Department of Health and Human Services on specified matters related to children with medically complex conditions.