Hi rcandrews 81,
If you entered your bank information for direct debit in order to make your payments and your returns were successfully submitted through e-file and accepted by the IRS, you do not need to mail in anything to the IRS. You are all set!!
Just in case, though, if you have a problem for some reason, refer to these instructions for printing out your 1040-V vouchers:
https://ttlc.intuit.com/replies/3300702
