What action items for W2C issued to correct employer HSA contribution amount after I already filed my tax return?

[S8NpTl]

I just received my 5498-SA from my HSA bank and the total contribution differs from the box 12c on my W2. I made no employee contribution so the entirety of the contribution were from my employer, and W2 box 12c and 5498-SA amount should match up but didn't. 

I had contacted my employer and they are issuing a W2C to correct the box 12c to the correct number reported in 5498-SA. I had already filed my tax return using the original W2 12c amount.

Both the correct and incorrect amounts were definitely under the contribution limit.

Do I need to file an amended return? Do I contact IRS directly?

[Anonymous · Accepted solution]

are the employer contributions to the HSA part of a salary reduction plan.  if so, then by changing the HSA amount your wages in box 1 could change.   if they do, this will require filing an amended return.      on the other hand if the only change on the W-2 is the HSA amount, I would not file an amended return unless line 2 on form 8889 is more than line 13