For fully insured plans, the carriers are responsible for sending Form 1094-C and 1095-C.

For self-insured plans, the plan sponsor is responsible for sending these forms to the State of California as furtherance of ACA compliance.  The forms are the same (in design) as the federal forms, and an employer may submit the federal form for state reporting purposes.

However, while federal forms are due March 2, 2021, the state forms are due February 1.