Do Social Security payments count as income for computing insurance plan subsidies?
Social Security payments are deducted from AGI, but added back in for MAGI. Therefore they generally do count as income for ACA cost assistance.
Non-taxable Social Security benefits(1) (Line 20a minus 20b on a Form 1040) are part of MAGI. “Social Security benefits” includes disability payments (SSDI), but does not include Supplemental Security Income (SSI), which should be excluded from MAGI.