Retirement, disabled adult child, divorced spouse and calculation of benefits. One of the unplanned consequences when I retired at 63.5 was that my daughter-DAC was switched from SSI to SSDI. Her benefit is a relatively robust $1350 a month vs. $750 on SSI. My ex-wife is still working and will retire in a few years. When the ex-spouse retires will the DAC payment go down because of the ex wife’s share of my SS retirement pie reduces the DAC share? Will the DAC payment go down but then perhaps up again because of payment to the DAC from the ex-wives SS retirement pie?
No. Auxiliary and survivor benefits paid to a divorced spouse do not count against the family maximum benefit (FMB) on a worker's record. Therefore, if your ex-wife qualifies for divorced spousal benefits from your account it couldn't cause your daughter's benefit rate to go down.
The maximum amount that can be paid to a disabled adult child (DAC) on the record of a living parent is 50% of the parent's primary insurance amount (PIA). A person's PIA is equal to their Social Security retirement benefit rate if they start drawing their benefits at full retirement age (FRA). If a child/DAC potentially qualifies for benefits on the record of more than one parent, they can't be paid on both accounts at the same time. So, the only way that your daughter's benefit rate could increase as a result of your ex-wife filing for her benefits is if your ex-wife's PIA is higher than your PIA.