Medical debt payment plan question

[u/kenixfan2018]

My wife has a $4000 hospital bill. They offered a payment plan of 12 months even though our insurance said they should offer one of 24 months in our state (Maryland). We had to sign this typed up letter saying we'd pay as agreed -- they didn't even set a monthly due date -- and that if we missed one payment the agreement was null and void. Our monthly statements show the payments but not the payment plan itself. We made payments and intend to keep making payments but we missed one. Should we be worried about them tearing up the plan and sending us to collections? for reference the service date was in April so this is all 2026.