839.1206—How do I submit a claim under this subpart?
        
        (a) 
         No specific form is required. Your request must be in writing and contain the following information:
    
    
    
    
    
    
        
        (5) 
         It must include any information you believe OPM should consider, such as cancelled checks or other evidence of amounts you paid.
    
    
        
        (b) 
         Send your claim to: Office of Personnel Management, Retirement and Insurance Service, ATTN: FC Section, Washington, DC 20415-3200