The ASEC’s SSI question (INCSSI) asks
How much did (name/you) receive (monthly/quarterly) in Supplemental Security Income payments in {year}?
They do not ask about SSI state supplements (SSP) separately.
Do we know whether respondents typically include SSP payments when answering this question?
The 2022 ASEC technical documentation provides additional guidance for this question. INCSSI corresponds to Q57c in the questionnaire which asks respondents to report their SSI income. In Q57a in the previous section, respondents are asked whether anyone in the household received SSI payments. This question includes an accompanying note that adds that “SSI are assistance payments to low-income aged, blind and disabled persons, and come from state or local welfare offices, the Federal government, or both.” Any state supplements to SSI therefore should be included in the amount reported in INCSSI.