216.81—Who is eligible for a parent's annuity.
        
        (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:
    
    
    
    
        
        (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
    
    
    
        
        (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:
    
    
    
    
        
        (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:
    
    
    
        
        (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
    
    
    
        
        (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
    
    
    
        
        (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.