We do not.

HI Dorothy! You do not -- but you will need to have them fill out a W9 for tax purposes. I also recommend a simple agreement that includes info about Workers Comp (do they provide their own coverage) and other understandings of the arrangement. https://www.irs.gov/pub/irs-pdf/fw9.pdf

Cheers, Colleen 

No, and it could be a problem if you do. I-9's are for employees.  Contractors are not your employees.