There is a difference between being incorporated, and being an LLC.
Give them a W-9 to fill out and have them give it back to you. You should do this before you pay them (ideally before they do any work for you).
In box 3, if they check "C Corporation" or "S Corporation", NO, you do not need to issue a 1099-MISC for their services.
If they are just an LLC that has not made the election to be taxed as a corporation (they would not check the corporation boxes), then YES, you do need to issue them a 1099-MISC for their services.
https://www.irs.gov/pub/irs-pdf/fw9.pdf
