Drug-Free Indian Health Service Act of 2017 This bill requires the Department of Health and Human Services (HHS) to implement mandatory random drug testing for Indian Health Service (IHS) employees who provide health care or administrative services to patients at IHS health care facilities. Officers of the Commissioned Corps of the Public Health Service are exempt from this drug testing. Each employee must be tested at least once per year for specified drugs. HHS must notify employees of the implementation of this drug testing. Employees selected for drug testing must be notified of their selection on the same day as the testing. Employees found to have engaged in illegal drug use, through testing, direct observation, evidence from a conviction, or voluntary admission, are prohibited from providing services to patients and referred to the HHS Employee Assistance Program (EAP). At the discretion of HHS, an employee may return to duty after obtaining counseling or rehabilitation through the EAP. HHS may initiate an adverse action, including removal, against an employee engaged in illegal drug use unless the employee voluntarily admits to illegal drug use, ceases such activity, and obtains counseling or rehabilitation through the EAP. Employees who refuse to submit to drug testing are prohibited from providing services to patients and are subject to adverse action.