Thank you for the detailed reply. It does confirm what I read and my calculations.
To clarify a few things for the benefit of your reply and others, in my original post, I mistakenly listed her Total Income (including her SS income) as $24K. When I re-reviewed all her files, it was actually $21K, as I correctly stated in my second post. So, subtracting her SS income of $15.5K from that $21K, her true AGI for calculating if she needs to file or not (which excluded her SS income) is only $5.5K, which as you noted, is way below the $14,050 filing threshold for someone single and over the age of 65. In reality, her husband passed away several years ago and she has never remarried, so technically, her filing status would not be Single, but as a Qualified Widow, which bumps that threshold filing requirement number up to $26,100 per IRS Publication 554. She is also still well below the $25,000 limit number if you do the 1/2 her SS income plus her total AGI including interest calculation: (($15,500/2) + $5,500) = $13,200 < $25,000.
