If you were older than 59-1/2 before you received a lump sum from a qualified employee retirement plan, you may have some other options that can reduce your tax bill. To use any of these special treatments, you must complete IRS Form 4972 and attach it to your tax return.
The file is in Adobe Portable Document Format (.pdf), and you will need the free Acrobat Reader to view and print the files.
Form 4972, Tax on Lump-Sum Distributions
Federal Income Tax Obligations