CMS 1500 claim form billing instruction Part 4

BLOCK 11A INSURED'S DATE OF BIRTH

CMS 1500 claim form billing instruction Part 2

CMS 1500 claim form billing instruction Part 3

CMS 1500 claim form billing instruction Part 1

Enter the insured's birth date (MMDDCCYY) and sex, if different from block 3.
BLOCK 11B EMPLOYER'S NAME OR SCHOOL NAME
Enter the employer's name, if applicable. If there is a change in the insured's insurance status, e.g., retired, enter the six - digit retirement date (MMDDYY) preceded by the word "RETIRED."
Completion of this field is conditional when the beneficiary has insurance primary to Medicare. 

BLOCK 11C INSURANCE PLAN NAME OR PROGRAM NAME