Answer:

Employers filing 10 or more information returns, including Forms W-2, must file electronically unless granted a waiver by the IRS. All employers are encouraged to file Forms W-2 electronically.

The information returns that count toward the 10-return threshold are:

Forms W-2, whether filed on paper or electronically, are filed with the Social Security Administration (SSA). For specifications for filing Forms W-2 with the SSA, visit SSA.gov/employer or call 800-772-6270 (TTY 800-325-0778)