My son 17, and his brother (not mine) receive survivor benefits from their deceased father. His brother who lives in another state, turned 18 and graduated from HS last month. Will my son's benefit increase? Or are the boys eligible through college until age 22?
Survivor benefits can be paid to eligible children who are a) under age 18, or b) 18 to 19 and attending high school, or c) any age if they became disabled prior to age 22. A child who is age 18 or older and in college wouldn't qualify for survivor benefits unless they're disabled.
If only 2 children and no other survivors have been drawing benefits on their deceased father's record, then your son's benefit rate would not increase when his brother becomes ineligible for benefits. The maximum benefit rate for a surviving child of a deceased worker is calculated at 75% of the deceased worker's primary insurance amount (PIA). The family maximum benefit (FMB) that can be paid on a deceased worker's record is always at least 150% of the deceased worker's PIA, so up to 2 children can collect their full benefit rates without being reduced by the FMB.
Therefore, assuming that the 2 children you mentioned are the only survivors who've been receiving benefits on their father's account, then your son is already being paid his full benefit rate and his rate won't increase when his brother's benefits stop.