On IRS Form 1095-C, there is a section for dependent information (Part III).
You will complete this section ONLY if your company’s policy is self-insured. If it is not, you do not need to put anything in Part III of Form 1095-C.
Part III was added in order to track dependent coverage for self-insured plans – so that an employer would not also have to produce and file IRS Forms 1094-B and 1095-B. The instructions for IRS Form 1095-C are specific:
“Complete Part III ONLY if the employer offers employer-sponsored self-insured health coverage in which the employee enrolled.”