Is there any data on costs/losses associated with non payers in the health care system?

My google skills are limited and I haven’t found any data on this.

The alleged cost of non payers is a frequent argument on the rising cost of health care.

I find this hard to swallow. Never have I heard of an actual source or number. So any data, whether from one facility, the cost in a state, or per organization would be of interest to me.