Groups representing people with hemophilia filed a civil rights complaint Tuesday against health insurer Wellmark for leaving the Obamacare exchange in Iowa to avoid paying the medical bills of patients with the disorder, including one patient whose medical bills amounted to $1 million a month.

The complaint, filed with the Office for Civil Rights at the Department of Health and Human Services, says Wellmark violated Obamacare by preventing people with hemophilia from accessing coverage, first by only selling plans in certain counties in Iowa and then by declaring it wouldn’t sell these plans in the entire state for 2018.