There is an income threshold: $64,000 for 2016, which the IRS says covers ~70% of tax payers.
If you make less than that, the "Free File Alliance" let you submit a simple federal return for free using their software. They may try to upsell you on various things and may charge for a state return too.
Above that threshold, your only free options are the paper forms or the "Free Fillable Forms" online. The latter option is really simple. It will copy some numbers from place to place and does some basic math, but beyond that it is very similar to filling in the paper form--it won't help you optimize your return or anything like that.
If you make less than that, the "Free File Alliance" let you submit a simple federal return for free using their software. They may try to upsell you on various things and may charge for a state return too.
Above that threshold, your only free options are the paper forms or the "Free Fillable Forms" online. The latter option is really simple. It will copy some numbers from place to place and does some basic math, but beyond that it is very similar to filling in the paper form--it won't help you optimize your return or anything like that.
More here: https://www.irs.gov/uac/free-file-do-your-federal-taxes-for-...