When depositing to an HSA, is there a difference in the taxes paid if you do pre-tax direct deposit via employer versus a post-tax (deductible) deposit on your own?

[bja1288]

I have cash on hand that I want to put in my HSA. I'm just curious whether it is better to fill up the HSA via direct deposit through my employer, which is pre-tax, or if I should just use cash on hand because it is deductible (even if I don't itemize). If there is no difference tax-wise, then I assume I should just deposit the cash.

[Opus 17 · Accepted solution]

When  making payroll deductions, you are also removing that income from social security and medicare taxation, so payroll deductions save about 7.65% more taxes than making after-tax contributions and deducting them on your tax return.

Of course, if you want to contribute for last year, the only way to do it is after-tax.

[bja1288]

Thanks, that's exactly what I was looking for.