Get your taxes done using TurboTax

Correct...  Then you select "Deferred Social Security Tax" and click "next."  Then what do you select? (Hint...  You are required to select which month your payment applies to.  You can't leave this blank)

 

The point here is, if you want to pay electronically (which I assume most of us do) and given that the IRS has said it is important to designate your payment properly as "deferred social security tax," and not comingle it with other tax payments, the IRS has yet to issue clear instructions on how to do this.  It seems like the only safe way to clearly designate is to mail a paper check and writ it in the memo (assuming someone will read it).