The subscriber number would be your insurance policy number, or ID number. It should be displayed on your insurance card.
The federal identification number is a nine-digit number assigned by the IRS in this format: XX-XXXXXXX. It should be located on the card, as well.
If you can't locate these numbers, contact the customer service number on the card.
If you have government-subsidized insurance, you won't always get a 1099-HC.