Below are the IRS 1099-Misc. rules regarding paying someone for services they provide. 

File Form 1099-MISC for each person to whom you have paid during the year:

• At least $10 in royalties or broker payments in lieu of dividends or tax-exempt interest.
• At least $600 in:
  • Rents.
  • Prizes and awards.
  • Other income payments.
  • Medical and health care payments.
  • Crop insurance proceeds.
  • Cash payments for fish (or other aquatic life) you purchase from anyone engaged in the trade or business of catching fish.
  • Generally, the cash paid from a notional principal contract to an individual, partnership, or estate.
  • Payments to an attorney.
  • Any fishing boat proceeds.

In addition, use Form 1099-MISC to report that you made direct sales of at least $5,000 of consumer products to a buyer for resale anywhere other than a permanent retail establishment.

Source: IRS Rules for 1099-Misc