I tried to login & view the status of a return, by going directly to their website. The site wouldn't recognize my username/password. It was ONLY, when I went back to IRS.GOV, and used their link to FREE1040TaxReturn.com - that my username/password actually worked.
Also, your Federal Tax Return is FREE, when you go to their site via the IRS.GOV link. If you go directly to their site, you will have to pay. So, make sure that you use the link.
I sent their Customer Service a note about this, asking if they could place some message on their website login area, to reflect this possible login issue. Hopefully, they will fix the issue, so that other people can quickly access what they need.