The Denver Post reports the Denver-based airline has a five-year lease for 14 gates at the airport that expires at the end of 2016. The airline wants to downsize to eight gates and reduce the amount of space it has by nearly 11,000 square feet under a proposed lease amendment.
City documents say the proposed change would save the airline $3 million annually.
In 2014, Frontier Airlines announced it would offer lower fares and began decentralizing operations away from Denver.
An airport spokesman says Frontier's gate reduction could help the airport save money and meet deadlines on improvement projects.