Crucially, those already on a 10% withholding plan will not be affected by the new 100% withholding rate. However tax refund offsets could begin soon.

Taxes on Social Security benefits have gotten a lot of attention over the last few months, ever since President Trump vowed to eliminate them on social media. If you owe them, you probably know they can cost you quite a bit. The IRS taxes up to 85% of some seniors' benefits at ordinary income tax rates, which can amount to thousands of dollars.

Tax season usually brings a refund check for most workers, but if you're retired, you could wind up owing the IRS.