I am seeing articles online that say your HSA contributions should reduce your adjusted gross income. That doesn't show true on any of my returns, is there a catch?

There is a bit of a catch.  Assuming you meet the qualifications to make a contribution to your Health Savings Account (HSA), for the contribution to be deductible, you must have made the contribution directly to the HSA with after-tax dollars.  

When contributions are made to your HSA through payroll deductions (reported on your W-2 in box 12 with code W), they are done with pre-tax dollars and therefore do not show on your tax return as a deductible contribution.  Instead, your taxable income in box 1 of your W-2 is lower than it would have been without the HSA contribution.

That clears it up, thank you so much!