"[If] the individual is [a non-resident alien (NRA)] at the time of distribution, the NRA withholding rules apply, even if the individual spent all or part of his/her related service working in the United States. Assuming the NRA withholding regime applies, a flat 30% withholding rate generally is imposed on the portion of the distribution that is attributable to (i) all earnings that accrued on the participant's benefit, and (ii) contributions made with respect to the participant's period of service in the United States. Any contributions made with respect to the NRA's period of service outside of the United States are not subject to US income tax withholding. The IRS has provided special guidance on applying this concept to defined benefit plans."