Thanks for reaching out about this!

At present, the only thing that should be holding up a prior year e-file is whether or not there is an extender present. If there is an extender present, the prior year return will not e-file at this time.

We are aiming for mid to late March for the high impact items, this being dependent on the IRS' updated forms/instructions.

As far as submitting amended returns, the IRS does not currently allow federal Form 1040X to be filed electronically at this time.

It is my hope this answers your questions!