the number of days of the partial emergency family relief period by the number of days of the month during which the majority of the emergency family relief period occurs, or, if the emergency family relief period is an even number of days, by the number of days of the shorter month during which it falls. (c) Limitations (1) Credit phase out The amount of the credit allowable under subsection (a) shall be reduced (but not below zero) by $50 for each $1,000 (or fraction thereof) by which the beneficiary’s modified adjusted gross income exceeds the threshold amount. For purposes of the preceding sentence, the term modified adjusted gross income means adjusted gross income based on the most recent information submitted by the beneficiary in a form deemed appropriate for the application process by the Secretary of the Treasury and increased by any amount excluded from gross income under section 911, 931, or 933. (2) Threshold amount (A) In general For purposes of paragraph (1), the term threshold amount means— (i) $100,000 in the case of a joint return