New York Consolidated Laws, Workers' Compensation Law - WKC § 70. Excess or catastrophe insurance;  public group self-insurance plans

a. the public group self-insurer, the county and each participant shall remain liable in the manner provided in the plan for claims made prior to the date on which the plan joins the public group self-insurer;  and

b. the committee or administrator shall establish, before the plan joins the public group self-insurer, a method, which may be amended annually thereafter, by which to apportion among the participants in the plan the cost of its membership in the public group self-insurer and all claims made after the date on which the plan joins the public group self-insurer, and each participant in the plan shall pay its respective share of the cost to the county treasurer, who shall pay the public group self-insurer on behalf of all plan participants.