Connecticut
For single taxpayers, Social Security income is fully exempt, as long as they have an adjusted gross income of less than $75,000. The same goes for married taxpayers who are filing jointly and have federal AGI of less than $100,000.
Taxpayers who don’t fall into these categories can still deduct 75% of their federally taxable Social Security benefits on their Connecticut tax return. Here, most items are taxed at 6.35%, and localities aren’t allowed to add anything more to that. In Connecticut, there’s an estate tax with a $9.1 million exclusion for this year. The tax due is no more than $15 million.