My brother received a corrected w2 after he filed his taxes last year, but he didnt amended his tax return. how does he have to do this year?

[Ashby · Accepted solution]

He should still amend his return from 2017. He has up until 4/15/2021 to amend a 2017 tax return and claim a refund.

He cannot add this corrected W-2 to his 2018 taxes. 

Also, he can still file his 2018 taxes without having completed the amendment to his 2017 return.