A small New Mexico health insurer is suing the Trump administration for restarting an Obamacare payment program that will require it to pay out millions of dollars to larger, more established insurers.

New Mexico Health Connections, a health insurance co-op, filed suit Monday in the U.S. District Court in Albuquerque on the grounds that the Trump administration didn’t follow rule-making procedures in setting up the program. It also is following up on a previous lawsuit saying that the formula used to calculate the payments is “arbitrary and capricious.”