Thank you @MindyB for your knowledgeable and timely response to my question. I did receive the 12C letter you reference. As you point out there must have been some glitch with my electronic signature packet.
As noted in my original post, my federal income Tax Return (Form 1040) was filed electronically through TurboTax (TT) on 31 March 2025; received electronic confirmation (via TT) the return was accepted by the IRS on 31 March. I responded promptly to an IRS identity verification request on 20 April 2025, via video call (ID.me); thereafter, IRS website confirmed initial verification was complete. Despite my 20 April identity verification, the return remained in limbo for more than 350 days. The IRS had the return, had verified my identity and was processing it, one has to wonder how something as straightforward as a missing or corrupted original signature packet would take so long to resolve.
I appreciate you making the time to respond to my question.
