How do you know if someone else filed using your SSN?

[dena-saper-gmail]

My return was rejected because my AGI and/or PIN was wrong. My AGI was correct and the system didn't ask me for last year's PIN. I'm concerned.

[DoninGA]

You would have received a rejection message that the Social Security number was on another tax return.

Your error is for the 2019 AGI only.

Try entering a 0 for the 2019 AGI and e-file again.

[lcoix]

You should get a transcript and see what's been filed: https://www.irs.gov/individuals/get-transcript