a08505a6_Medical_billing__November_2010__Notes
[BlockNo.] 9b [Block Name] Other Insured’s Date of Birth and Sex [Block Code] A [Notes] 
If a secondary insurance exists, enter the other insured’s date of birth. Please make sure the date is in an eight-digit MMDDCCYY (month, day, century, and year) format (e.g., 03011978) and indicate the patient’s gender by placing an X in the appropriate box.
CMS 1500 claim and UB 04 form- Medical billing: November 2010
Notes