(a) Where the employee is not survived by a widow(er), or child who is or ever could be entitled to an annuity as described by subpart G or H of this part, a parent of the deceased employee is eligible for both the tier I and tier II components of an annuity if he or she:

(1) Is age 60 or older;

(2) Has not married since the employee died;

(3) Received one-half of his or her support (as defined in part 222 of this chapter) from the employee at the time the employee died; and

(4) Files proof of support as provided for in paragraphs (b)(4) and (b)(5) of this section.

(b) Where the employee is survived by a widow(er), or child who is or ever could be entitled to an annuity as described by subpart G or H of this part, a parent of the deceased employee is eligible for an annuity consisting of the tier I component alone if he or she:

(1) Is age 60 or older;

(2) Has not married since the employee died;

(3) Is not in receipt of an old age benefit under the Social Security Act equal to or exceeding the amount of the parent's tier I annuity amount before it is reduced for the family maximum but after the sole survivor minimum is considered;

(4) Received at least one-half of his or her support (as defined in part 222 of this chapter) from the employee either:

(i) When the employee died, or

(ii) At the beginning of the period of disability if the employee has a period of disability (as explained in part 220 of this chapter) which did not end before death; and

(5) Files proof of support with the Board within 2 years after either:

(i) The month in which the employee filed an application for a period of disability if support is to be established as of the beginning of the period of disability; or

(ii) The date of the employee's death if support is to be established at that point.

(c) The Board may accept proof of support filed after the 2-year period for reasons which constitute good cause to do so as that term is defined in part 219 of this chapter.