Box 11 and 11a to 11d: Insured policy group number and related details
By Dr. Daniel Turner, DC · Reviewed September 2, 2026
What goes in Box 11 and 11a to 11d of the CMS-1500?
The policy or group number of the primary insurance, the insured’s birth date and sex, employer or plan names where applicable, and the pivotal 11d question: is there another health benefit plan.
What does Box 11 and 11a to 11d mean for chiropractic billing?
Group numbers move when employers change carriers each January, and stale group numbers ride along on every claim until someone updates the chart. 11d answered yes obligates Box 9; answered wrong in either direction it either hides a secondary payer or invents one.
The mistakes that turn this box into denials
- ✗Prior year group numbers after a January plan change
- ✗11d yes with Box 9 left empty
- ✗Policy number repeated where the group number belongs
The denials this box causes
How Cervica fills Box 11 and 11a to 11d
Cervica generates the CMS-1500 and its electronic 837P equivalent from the chart and the payer's own rules: identifiers from the verified insurance record, modifiers and codes per payer, and pre submission scrubbing that flags exactly the mistakes listed above before a claim leaves the building.
Related boxes
- →Box 9 and 9a to 9d · Other insured information
- →Box 1 and 1a · Insurance type and insured ID number
- →Box 4 · Insured name
General information for billing teams, not billing advice for any individual claim. The NUCC's 1500 Claim Form instructions and each payer's companion guides control.