I'm 70 yrs old, I have $100K IRA, and I want to liquidate all of it. My question: Can I have the option of paying the tax later instead of now? Thank you for the help.

If you liquidate all of it (by which I assume you mean you would cash it all in) you will owe income taxes on the full amount of $70K. The plan administrator should automatically withhold 20% off the top for taxes, so you would actually receive $56K in cash and have $14K already paid toward your 2011 federal taxes. If you think your actual tax bill may be higher than that you should file an estimated tax payment to avoid the shortfall. You can make an estimated tax payment at any time, but to avoid late payment interest charges you must file any estimated taxes owed by the end of the quarter when you receive the income (April 15, June 15, Sep 15 or Jan 15).

If you live in a state or locality that taxes 401(k) distributions you should also file an estimated tax payment with them as well. The amount to pay of depends on the tax rate for your taxable income level.