Indian Health Service Advance Appropriations Act of 2013 - Amends the Indian Health Care Improvement Act to require that for each fiscal year, beginning with FY2015, discretionary new budget authority for the Indian Health Services and Indian Health Facilities accounts of the Indian Health Service includes advance discretionary new budget authority for the following fiscal year.
Directs the Secretary of the Interior to include in documents submitted to Congress in support of the President's budget for each of those fiscal years detailed estimates of the funds needed for such accounts for the fiscal year following the fiscal year for which the budget is submitted.
Requires the President's budget to include information on estimates of those advanced appropriations.