Help with a "non-medically necessary" ambulance bill.

My Dad was transported to a hospital 60 miles away from home because he needed care at a more comprehensive hospital than what he had at home (that ride was covered). Once he had testing done, they determined he was beyond help and advised hospice. He didn’t want to stay in the hospital and fortunately we were able to arrange an ambulance ride to a hospice facility back at home. While this was wonderful for him and his family/friends, it was also determined not medically necessary (understood) and today my Mom got the bill for $2800.

Couple questions. Will that count toward her OOP max? My Dad was in the hospital for ~2 months and a week of that was in the ICU so I know we’ve definitely hit that $6500 OOP max but I wasn’t sure if this went toward it.

My Mom said she’s going to make some calls tomorrow but should she call the ambulance services first to see if they billed insurance? Or should she call insurance first?

Is there anything specific she should do to help minimize this bill or is she just out of luck?

Don’t get me wrong, getting my Dad back home so he could say goodbye to everyone in a beautiful setting was 100% worth it, but I just want to help my Mom with this added expense if possible. Thanks for any help, and if I should post this somewhere else please let me know!

Edit: she’s 63, has private insurance through work with a OOP max of $6500, zip code 48060. Income ~$48k, Dad was retired, 63, and on Mom’s insurance as well.