The royalty payments are from Germany and I was under the impression that the German intellectual property agency (GEMA) automatically deducts the taxes but my brother told me that that's not the case. I filed form 6166 and had my tax documents sent directly to the agency for certification of my US tax residency. Thank you for your help!
Yes, as a US citizen or resident, you have to report your worldwide income.
So your foreign royalty payments have toi be reported as income. If you have paid any foreign tax on them, you can claim the tax credit on form 1116.
Just a bit of clarification for others here, as I can see how it can be confusing and unclear to someone that doesn't undertsand inheritance.
Inherited foreign royalty payments.
The payments themselves are not inherited. It's the 'rights" to the payments that were inherited. But the payments to the one who has those rights are reportable on their tax return.