It all depends, and it is important to note these are two separate questions with separate dollar thresholds for each.
SS Benefits may or may not be taxable, depending on what other sources of taxable income you have during the year. To figure it out, the IRS has published a dollar threshold (different for single, married filing joint and others). If the number exceeds the threshold, the benefits must be included in a tax computation.
To figure if they are to be included or not, take ½ of the social security earnings for the year, and add to it any other taxable income earned during that year. If married, one must add the spouse’s other income too. If the number is greater than $32,000, some of your benefits may be taxable (and includable in the next step…do I have to file?)
To figure if you need to file a return, there is another dollar threshold to examine. It depends on your filing status and your age (and that of your spouse). In the case of spouses, both over 65 years of age, married filing jointly, a return was required if the gross income was at least $23,100 (for 2016). If in step 1 you determined that your SS benefits were not taxable, then they don’t count in figuring if you have a filing requirement.
This is more important that it may sound. For expats, a federal filing requirement may generate other additional forms, such as Form 8938, “Statement of Specified Foreign Assets” that would otherwise not be required to be filed.
As the year progresses, it is wise to keep track of your income and begin checking to see if you will be required to file a federal income tax return. Planning makes a difference! IRS Pub. 501 has all the details.