Why doesn’t the amount on my W-2 box 12w for HSA contribution (taxpayer) equal the amount in box 2 (total contributions made in 2018) on my 5498-SA from the bank?

[jfaike]

The difference is approximately $200 less on the w-2 than on the 5498-SA from the bank. Does this difference matter?

[BMcCalpin]

Without seeing your tax return, I cannot be sure, but please read the following:

The code W amount on box 12 on your W-2 includes what your employer contributed in 2018 PLUS what you contributed through payroll deduction in 2018.

Box 2 on the 5498-SA is

1. the sum of all contributions made in 2018 (both Code W and direct contributions)

2. any contributions that you made in 2018 for 2017

3. also includes any trustee to trustee transfers from an IRA to the HSA.

4. however, any excess contributions for 2018 are not included in Box 2.

So, for example, if TurboTax reported that you had $200 in excess HSA contributions, your code W amount would be the total amount sent to the HSA, and the box 2 (5498-SA) amount would be the net amount of the contributions after the excess was removed.

Unless you know of a reason why one of them is wrong, I would go with the W-2.