Oops - forgot the IRS guidance.
Excerpt From the instructions for Forms 1099-R and 5498
Nonresident Aliens
If income tax is withheld under section 3405 on any distribution to a nonresident alien, report the distribution and withholding on Form 1099-R. Also file Form 945 to report the withholding. See the Presumption Rules in part S of the 2016 General Instructions for Certain Information Returns. However, any payments to a nonresident alien from any trust under section 401(a), any annuity plan under section 403(a), any annuity, custodial account, or retirement income account under section 403(b), or any IRA account under section 408(a) or (b) are subject to withholding under section 1441, unless there is an exception under a tax treaty. Report the distribution and withholding on Form 1042, Annual Withholding Tax Return for U.S. Source Income of Foreign Persons, and Form 1042-S, Foreign Person's U.S. Source Income Subject to Withholding.
For guidance regarding covered expatriates, see Notice 2009-85, 2009-45 I.R.B. 598, available at
www.irs.gov/irb/2009-45_IRB/ar10.html.