For a distribution paid to you from an IRA, 10% is the default withholding. You have the option to decline withholding or to have more than 10% withheld. A trustee-to-trustee transfer (nonreportable) is generally the best choice, but if you want to do a distribution and rollover instead of doing a trustee-to-trustee transfer, request that no taxes be withheld if you will be rolling over the entire distribution.
If doing a trustee-to-trustee transfer, it's generally best to initiate the request at the receiving custodian so that they can tell the original custodian the proper way to transfer the funds.
