Educational Development for Troops and Veterans Act of 2017 This bill provides for eligibility of members of reserve components of the Armed Forces who are ordered to active duty for: (1) Post-9/11 educational assistance, (2) non-reduction in pay while serving in the uniformed services or National Guard, and (3) extension of the time limitation with respect to training and rehabilitation assistance for veterans with service-connected disabilities. The bill amends the Higher Education Act of 1965 to allow members of the Armed Forces and National Guard to defer principal payments on Federal Family Education Loans, William D. Ford Federal Direct Loans, and Federal Perkins Loans for the period (not to exceed 180 days) beginning on the date they receive a duty order in connection with a war, military operation, or national emergency and ending on the first day of service. (Currently, the payment of principal on those loans is deferred during the service period and for the 180-day post-service period.) The bill replaces the grant program for model programs to support veterans in postsecondary education with a grant program to assist in the establishment and operation of Veteran Student Centers. The annual educational assistance increase payable to certain Selected Reserve members shall not be less than the percentage by which the average cost of U.S. undergraduate tuition for an academic year exceeds the previous year's average cost. (Currently, such increase is Consumer Price Index based.) Post-9/11 educational assistance shall be prorated in any month in which a Reserve member is on both active and non-active duty, effective on or after August 1, 2016.