When selecting how I would like to pay an amount due for federal taxes, I am being told that the direct debit option is not available to me. Why would this be?

If you mean to pay the federal balance due then I highly recommend you choose to mail in a check and then pay directly online at the IRS web site instead so you pay less in fees.   If the debit card is connected to your checking account then do not use the card to avoid the fees.

https://www.irs.gov/payments

Critter, I am not trying to use a debit card.  I am trying to have the IRS directly debit my bank account through the turbo tax software.  Turbo tax says the option isn't available to me which I do not understand.  Your suggestion of paying directly on the IRS website is a good one.  Thank you, although still not sure why turbo tax won't allow me to sign up for it in their application.