Native Health Access Improvement Act of 2017 This bill amends the Public Health Service Act to require the Indian Health Service (IHS) to award grants to Indian health facilities for the prevention and treatment of mental health and substance use disorders. The IHS must establish a technical assistance center for grantees. In addition, this bill amends the Patient Protection and Affordable Care Act to define “Indian” for purposes of health insurance reform, exchanges, and subsidies. The definition includes individuals of Indian descent who are members of an Indian community served by the IHS and individuals considered by the Department of Health and Human Services to be Indian for purposes of eligibility for Indian health care services. Individuals included in the definition are eligible for special monthly enrollment periods on health insurance exchanges and elimination of cost sharing under individual health coverage for those whose income is not more than 300% of the poverty line. Under current law, only members of Indian tribes are eligible for these benefits. The bill amends the Internal Revenue Code to exempt Indians, as defined by this bill, from the requirement to maintain minimum essential health coverage.