From the IRS 590-A instructions for IRAs:
"However, for tax years beginning after 2019, certain non-tuition fellowship and stipend payments not reported to you on Form W-2 are treated as taxable compensation for IRA purposes. These amounts include taxable non-tuition fellowship and stipend payments made to aid you in the pursuit of graduate or postdoctoral study and included in your gross income under the rules discussed in chapter 1 of Pub. 970, Tax Benefits for Education.
