You can always withdraw more than you are required to from your IRAs and retirement plans.
However, if you fail to take at least the RMD for any year (or if you take it too late), you will be subject to a federal penalty. The penalty is a 50 percent excise tax on the amount by which the RMD exceeds the distributions actually made to you during the taxable year.
Example: You own one traditional IRA and compute your RMD for year one to be $7,000. You take only $2,000 as a year-one distribution from the IRA by the date required. Since you are required to take at least $7,000 as a distribution but have only taken $2,000, your RMD exceeds the amount of your actual distribution by $5,000 ($7,000 minus $2,000). You are therefore subject to an excise tax of $2,500 (50 percent of $5,000).
Technical Note: You report and pay the 50 percent tax on your federal income tax return for the calendar year in which the distribution shortfall occurs. You should complete and attach IRS Form 5329, "Additional Taxes on Qualified Plans (Including IRAs) and Other Tax-Favored Accounts." The tax can be waived if you can demonstrate that your failure to take adequate distributions was due to "reasonable error" and that steps have been taken to correct the insufficient distribution.
You must file Form 5329 with your individual income tax return, and attach a letter of explanation. The IRS will review the information you provide and decide whether to grant your request for a waiver.