If you are the insured's equitably adopted child, as defined in §404.359, you are considered dependent upon him or her if you were either living with or receiving contributions for your support from the insured at the time of his or her death. If your equitable adoption is found to have occurred after the insured became entitled to old-age or disability benefits, your dependency cannot be established during the insured's life. If your equitable adoption is found to have occurred before the insured became entitled to old-age or disability benefits, you are considered dependent upon him or her if you were either living with or receiving contributions for your support from the insured at one of these times—

(a) When you applied; or

(b) If the insured had a period of disability that lasted until he or she became entitled to old-age or disability benefits, at the beginning of the period of disability or at the time the insured became entitled to benefits.