In the rush to get you to the hospital, the ambulance personnel do not take down your insurance details. A few weeks later you may get a huge bill.
Before you pay the bill, turn the bill over and on the back of the letter there is normally a place to list your insurance coverage.
Take the time to fill this out and provide:
1)Your Medicare number
2) Your secondary insurance (if you have one)
3) Your supplemental insurance
Don't send a payment along with this information when you return the letter.
In a week or two you should receive a new bill with a reduced amount. You may have just saved yourself a few thousand dollars.