A group of transgender servicemembers, who served up to 18 years in the Air Force, are suing the military for depriving them of their retirement benefits after the Trump administration booted all transgender troops from the military's ranks.

In a lawsuit filed on Nov. 10, more than a dozen transgender servicemembers are asking a court to reinstate the pensions they say the Air Force promised them as they were forced out of the military, only to rip them away in the subsequent months.

President Donald Trump issued an executive order earlier this year ordering the Pentagon to oust all transgender troops.

Transgender soldiers who resigned of their own accord would receive "voluntary separation pay," according to Pentagon guidance. Those who didn't could be identified via "medical record reviews" and expelled.

Amid the purge, the Air Force told transgender troops in May that those being expelled after 15 to 18 years of service could apply for early retirement benefits. All the plaintiffs received their official retirement orders the following month.