File for free with Social Security only

Yes, Social Security income is included in the Free edition.  In fact, if Social Security is your only income, you do not have to file a tax return. 

Also, if Social Security is the only income you have you cannot e-file a return (unless you are Married Filing Separate).

If SS benefits are your ONLY income then you don't need to file a return at all UNLESS one or more of the following apply :

> you had insurance thru the ACA  to report (form 1095-A)

> you have dependents to claim for a refundable credit

> you had federal withholding from the SS benefits

> you have some other refundable credits to claim (like EIC based off the 2019 earned income)

If you still wish to file, add $1 of interest. That way, you'll be able to efile.