20 CFR 216.70: General.

The Railroad Retirement Act provides an annuity for the child of a deceased employee but not for the child of a living employee. The Act does provide that the child of a living employee can establish another individual's eligibility for a spouse annuity or cause an increase in the annuities of an employee and spouse. The eligibility requirements described in this subpart also apply for the following purposes, except as otherwise indicated in this part:

(a) To establish annuity eligibility for a spouse under subpart F of this part if he or she has the employee's eligible child in care;

(b) To establish annuity eligibility for a widow(er), or surviving divorce spouse or remarried widow(er) under subpart G of this part if he or she has the employee's child in care; or

(c) To provide an increase in the employee's annuity under the Social Security Overall Minimum Guaranty (see part 229) by including the eligible child.