@cactuspatchhill
Again, as in the above comments , you are getting a couple of things mixed up.
1. If you are less than full retirement age, and you keep working you begin taking benefits, your benefits will be reduced based on how much you work. There is a special rule if you start taking your benefits in the middle of the year, so that your later benefits are not reduced by your earlier work. This has nothing to do with how much income tax you pay on your benefits, and it only concerns income earned from working, not other kinds of nonwork income.
2. Your benefits are tax-free if they are your only income. If you have any other income from any source, including work, pensions, or something else, your benefits may be taxed based on the amount of your other income. There are no special rules for the first year of taking benefits, the calculation is strictly based on your total income.
So it is certainly possible that if you begin taking benefits late in the year, your benefits will be taxable, even though they might not be taxable in following years when you have lower total income.
