Form W-4P for survivor pension and tax filing requirements for a disabled adult

[Mateo101]

My brother is a disabled adult child with ~$16,200/year of SSDI and no other income. He started living in a group home January 2025; thus nobody will claim him as a dependent any longer.

Because of his disability, he is newly eligible for a small survivor continuance annuity payment from my mom's California school pension. This should be under $6000/year paid monthly for the rest of his life.  CalPers has issued him a W-4P to fill out.

1. Given this adjusted income picture, should we fill out the W-4P to indicate "no withholding" or something else?
2. Given this adjusted income picture, does he have to file a Federal or CA State tax return going forward?

Thanks much!

[Mateo101]

Correction. Meant to just say "My brother is a disabled adult..." without the "child".  He is 32-years old

[MaryK4 · Accepted solution]

The additional income will not create a filing situation for him for federal or state taxes (he would most likely need at least $25,000), so you can indicate exempt (No withholding) for him on the W4P.  

[Mateo101]

Thank you so much @MaryK4 !

I couldn't find much on the internet, but I did find the IRS ITA tool, which helped out a bit.