Aizawl, who scripted a fairytale league victory in the 2016-17 season, were the newly-promoted team in the 2015-16 season. They finished one point better off bottom-placed DSK Shivajians but neither team suffered the drop.
Aizawl were relegated because DSK had immunity but were later reinstated.
Sporting Goa and Salgaocar decided to withdraw from the league due to restructuring of the domestic league system in India. The two clubs had issued a joint statement which read,
"Over the past few weeks, Salgaocar Football Club and Sporting Clube de Goa have had several rounds of discussions and have deliberated the impact that the May 17th proposal will have on the state of the sport. It is clear that the proposal is highly discriminatory, goes against sporting merit, is unworkable for I-League clubs and hampers Goa, which is the best-represented state in the I-League, the most.
“Therefore, rather than waiting for another year to face the inevitable, Salgaocar Football Club and Sporting Clube de Goa have decided to take the painful decision to withdraw from the forthcoming edition of the I-League.”