@Asif333 , Generally there is no connection between taxabilty  of income and counting the income towards sponsoring a relative. However, what I understand the IHSS program to be is that it is focused towards the people ( elderly ?)  whom would otherwise be significantly & financially affected if they were required to pay for in home services.  Hence there is means testing involved . For sponsoring a relative  ( for entry and /or permanently staying in the USA), the requirement published on i-864P uses the same means testing ( 125% of poverty line ) and takes into account number of persons in the household -- thus if you live alone and wanted to sponsor your spouse you would have to meet ( for 2022) $22,887 income per year. It does not say anything about the source of the income or the taxability of the income. ---- see this -->2022 HHS Poverty Guidelines for Affidavit of Support | USCIS.

Also note that the  spouse that you sponsor , if he/she has an income or likely to have income, then that also would count towards the sponsoring amount.  You can also have other relatives  join you in sponsoring thus making sure there is enough to meet  the required amount.

Bottom line it is the total resource that matters , not whether it is taxed or not. 

Good Luck

Is there more I can do for you ?  

pk