@qbteachmtThanks. Your comments helped greatly. That's what I thinking too, after initially reading the instructions to 1040-NR line 4a and 4b (IRA Distributions), which instructed "See Lines 4a and 4b - IRA Distributions in the instructions for Form 1040 for details on IRA distributions." Treat it as ordinary taxable income.

Then, perhaps unfortunately, I came across an online article about tax treatment for IRA Distributions for non-resident filing 1040-NR that talked about the bifurcation treatment of IRA Distributions on 1040-NR into 2 separate parts: (1) "Original contribution" - treated as ECI up to the amount of contributions to the IRA and taxed at the regular graduated tax rates; & (2) "Investment earnings" - treated as passive income and at the unfavorable flat rate of 30%.  That what confused me, hence me coming over to this community to see how others here are reporting the IRA distributions on 1040-NR for their clients.

Here is the link to the article: https://hodgen.com/ira-distributions-for-noncovered-expatriates/