And Turbo Tax doesn't calculate the actual penalty. It is just an estimate. So you might get a bill for more from the IRS. Since you have the Desktop program you can check a box to let the IRS figure it for you. That's what I do.
If you have the desktop program you can switch to Forms Mode (click forms in the upper right (left for Mac)) and open the 2210 form. If the 2210 doesn't show up in the left column, click on Open Forms at the top of the left column. Type 2210 in the search box and open the 2210 form. Check box C to let the IRS calculate it.
