Then why not just wait until you're fully retired in January of 2019 to begin collecting social security and your reduced income (from not working) in 2019 will reduce your taxes for that year (and for 2018 also). You only have to wait two months because of your retirement in November. Also waiting will increase your social security payments, yes, even by the number of months. Why take a lump sum from your retirement? I would think that's going to raise your taxes, unless you roll that into an IRA or another retirement plan. Of course, consult with an accountant or other professional.