I've read that Turbotax will allow me to e-file 1099-NECs for contractors who work for me. Do I need a transmitter code (like IRS requires) to e-file thru Turbotax or no?

[VolvoGirl]

No.    How to prepare 1099 & W2
https://ttlc.intuit.com/community/forms/help/how-do-i-create-w-2-and-1099-forms-in-turbotax/00/25869

You need to give a 1099NEC to anyone you paid $600 or more to for the year. But not to corporations or for merchandise. You send the IRS a copy of the 1099NEC with the transmittal summary form 1096. These are due to the person by Jan 31 and to the IRS by Jan 31 also.

You can prepare W2 and 1099NEC & 1099MISC in either the Desktop Home & Business program or the Online Premium version using the QEF Quick Employer Forms.