We count income by determining countable income for each calendar month of eligibility. This means looking at income you received (or deemed to have received, see §2167) in a given month. We then apply exclusions appropriate to that month's income.
If your countable income is more than the FBR, you are not eligible for a Federal benefit. Since SSI payments are made on the first day of a month for that same month, we need to use an estimate of countable income to project your eligibility for that month.
We review the estimates (and revise them, if necessary) whenever there is a report of change or a redetermination.