How it works
A lump-sum pension paid directly to you usually has a mandatory 20% federal withholding taken up front, but your actual tax depends on your bracket — the lump sum stacks on top of your other income and can push you higher. This estimates the federal and state tax, what's withheld now, and the gap you may still owe or get back at filing.
Rolling the lump sum directly into an IRA avoids the 20% withholding and defers the tax, keeping the whole amount working.