I have a question that I can't find answered anywhere on the Internet, and hope you can answer it. If I use Form W-4V to withhold 7% of my social security benefit for federal income tax, will Social Security multiply that 7% times my gross benefit, or will they first subtract out Medicare Part B and Part D premium amounts? I thought I saw somewhere that they would apply the percentage to the net amount after the premiums are subtracted out, but now I can't find anything in writing. This makes a difference to how I fill out the form and how I budget. And maybe someone else would like to know the answer also. Thanks!

Hi,

I'm sorry, but I can't give you a definite answer. I thought that the withholding was based on the gross amount before other deductions, but I recently received a question from another reader that indicates the withholding is based on the net amount. Social Security's website isn't clear on this subject (https://www.ssa.gov/planners/taxwithold.html), so I'm afraid you'll need to check with Social Security for an answer.

Best, Jerry