When is the deadline to amend 2021 return?

[llbball]

After I filed my 2021 taxes, my employer (in April!) sent out an amended W2.  In Turbo Tax, I then completed an amended return and learned that I owe more money so I didn't file it then.  I'm curious when the deadline is to file this amendment.  I've read you have 3 years, so would that be this year I need to file that, or do I have another year to wait? 

[MinhT1]

You have three years from the date you filed your return or two years after you paid the tax due (whichever is later) to file an amendment.

In theory, for tax year 2021, you have until April 15, 2025 to file an amended return.

However, as you did not report a form W-2, the IRS may find out before by computer matching (as the IRS has a copy of all forms W-2) and will sent you a notice for back taxes, penalty and interest.