Section 222.56 - When a grandchild or stepgrandchild is dependentAn employee's grandchild or stepgrandchild, as described in § 222.36 , is considered dependent on the employee if the requirements in both paragraphs (a) and (b), or paragraph (c) of this section are met:
(a) The grandchild or stepgrandchild was living with the employee before the grandchild or stepgrandchild attained age 18.(b) The grandchild or stepgrandchild is living with the employee in the United States and receives at least one-half of his or her support from the employee for the year before the month in which-(1) The employee could become entitled to an age and service or disability annuity under the Social Security Act (treating his or her railroad compensation as wages under that Act); or(2) The employee dies; or(3) The employee becomes entitled to a period of disability that lasts until he or she could become entitled to a social security benefit as described above or until he or she dies.(c) In the case of a grandchild or stepgrandchild born within the one-year period referred to in paragraph (b) of this section, at the close of such period the child must have been living with and receiving at least one-half of his or her support from the employee for substantially all of the period that began on the date the grandchild or stepgrandchild was born. "Substantially all" is defined in § 222.53 .