4050.4—Diligent search.
        
        (a) Search required.
         A diligent search must be made for each missing participant before information about the missing participant or payment is submitted to the PBGC pursuant to  § 4050.6.
    
    
    
        
        (1) 
         Begins not more than 6 months before notices of intent to terminate are issued and is carried on in such a manner that if the individual is found, distribution to the individual can reasonably be expected to be made on or before the deemed distribution date;
    
    
        
        (2) 
         Includes inquiry of any plan beneficiaries (including alternate payees) of the missing participant whose names and addresses are known to the plan administrator; and
    
    
        
        (3) 
         Includes use of a commercial locator service to search for the missing participant (without charge to the missing participant or reduction of the missing participant's plan benefit).