Unexpected Check

I don't understand medical billing. Sutter Hospitals mailed me a $1,500 check. I have no earthly idea why.

I’m like a deer in the headlights with this stuff. I was impressed with the original hospital bill: $91,000, minus an $84,000 “adjustment” (that’s all it said). Of the remaining $7,000, I paid $2,000 and the insurance company paid $5,000. But if I get a $1,500 refund, then all I pay is $500 (plus an additional $5,000 paid separately to doctors). None of it makes any sense to me, but it seems better than paying $91,000. It’s like playing “Wheel of Fortune.”