Do admin/transaction fees in an HSA investment account count towards the annual contribution limit? I.e., could I contribute the IRS limit + $25 to cover a $25 fee?

[Critter]

No, you cannot contribute more than the max allowed.

[dmertz]

Provided that the HSA custodian bills separately for administration and maintenance fees, they can be paid with non-HSA funds and some HSA custodians allow you to pay the fee at the same time as you make your contribution.  However, if the HSA custodian deducts administration and maintenance fees from the balance in the HSA, you cannot pad your contribution beyond the limit that you are eligible to contribute to cover the fees.  Check with your HSA custodian to determine your fee-payment options.