Think of these "free fillable forms" as a spreadsheet. Numbers go in boxes, other boxes compute themselves and nothing more. Now go look at the IRS instructio

Think of these "free fillable forms" as a spreadsheet. Numbers go in boxes, other boxes compute themselves and nothing more. Now go look at the IRS instructions for a typical schedule. Here's a common one, Schedule A for itemized deductions: https://www.irs.gov/pub/irs-pdf/i1040sca.pdf https://www.irs.gov/pub/irs-pdf/i1040sca.pdf It's a mere 17 pages including lookup tables. Pretty lightweight. Some go way longer. Now, is all of this information and logic put into the free form calculator? It's not. So you need to read along with these instructions and follow all of the conditionals and detours described inside. This is what you're buying when you buy a tax prep program, and this is what's missing from the free options.