When will the IRS start accepting e-filed returns?
You can file your federal return when you have all your 2018 tax info (W-2s, 1099s, etc.) and all the tax forms and schedules in your return have been finalized (many IRS forms are ready now, and most should be ready by late January).
The IRS will start processing the backlog of e-filed returns on Monday, January 28, 2019.
I heard some people already got accepted – what's going on?
The IRS always processes a test batch about a week before the official processing date. These returns do not necessarily follow the "first in, first out" rule; instead, they are selected to test specific scenarios such as itemized returns, returns that contain a certain form, and so forth.
This means a handful of taxpayers may get accepted before the official January start date, even if they filed after you did. However, tax refunds – including those in the test batches – won't be processed until after the official start date.
Note: If your return is among those that the IRS processes early as part of its testing, your tax refund (if any) won't be processed until after they start accepting everyone's e-filed returns.