Benefits shall be determined for each month. The amount of the monthly payment will be computed by reducing the benefit rate (see §§ 416.410 , 416.412 , 416.413 , and 416.414 ) by the amount of countable income as figured under the rules in subpart K of this part. The appropriate month's countable income to be used to determine how much your benefit payment will be for the current month (the month for which a benefit is payable) will be determined as follows:
Example 1. Mrs. X's benefit amount is being determined for September (the current month). Mrs. X's countable income in July is used to determine the benefit amount for September.
Example 2. Mr. Z's SSI benefit amount is being determined for January (the current month). There has been a cost-of-living increase in SSI benefits effective January. Mr. Z's countable income in November is used to determine the benefit amount for January. In November, Mr. Z had in-kind support and maintenance valued at the presumed maximum value as described in § 416.1140(a) . We will use the January benefit rate, as increased by the COLA, to determine the value of the in-kind support and maintenance Mr. Z received in November when we determine Mr. Z's SSI benefit amount for January.
Example 3. Mr. Y's SSI benefit amount is being determined for January (the current month). Mr. Y has Social Security income of $100 in November, $100 in December, and $105 in January. We find the amount by which his Social Security income in January exceeds his Social Security income in November ($5) and add that to his income in November to determine the SSI benefit amount for January.
Example: Mrs. Y applies for SSI benefits in September and meets the requirements for eligibility in that month. (We use Mrs. Y's countable income in September to determine if she is eligible for SSI in September.) The first month for which she can receive payment is October (see § 416.501 ). We use Mrs. Y's countable income in October to determine the amount of her benefit for October. If Mrs. Y had been receiving SSI benefits through July, became ineligible for SSI benefits in August, and again became eligible for such benefits in September, we would use Mrs. Y's countable income in September to determine the amount of her benefit for September. In addition, the proration rules discussed above would also apply to determine the amount of benefits in September in this second situation.
Example: Mrs. Y was initially eligible for payment of SSI benefits in October. Her benefit amount for November will be based on her countable income in October (first prior month).
Example: Mrs. Y was initially eligible for payment of SSI benefits in October. Her benefit amount for December will be based on her countable income in October (second prior month).
20 C.F.R. §416.420