I originally had 15 percent withheld from my social security check 5 years ago. Will social security automatically lower the withholding rate to the new rate of 12 percent or will they grandfather my old rate of 15 percent in? Do I need to fill out a new W-4V form if I still want 15 percent withheld or is this not possible?
That's a good question, and I don't know the answer. Social Security's operations manual states that new tax withholding requests can only be accepted in rates of 7, 10, 12 or 22 percent, but it's silent on the issue of whether or not people who previously requested withholding rates of 15 or 25 percent can opt to continue those rates (https://secure.ssa.gov/apps10/poms.nsf/lnx/0202410015). You'll probably need to check with Social Security to see if they can answer your question.