Deductions & credits

Go look here:

<a rel="nofollow" target="_blank" href="https://turbotax.intuit.com/personal-taxes/online/">https://turbotax.intuit.com/personal-taxes/onlin...>

You pay the differential between where you're at - assuming you already have paid - and where you end up.  ("State" is extra to the prices shown.)

If you haven't paid then it could be cheaper to simply go out and purchase a desktop product - they are widely discounted by Amazon an other - since the desktop products all support the same Forms, Schedules and Worksheets.