If a company is filing a new or "introductory rate filing," then the company will permitted to use countrywide experience in support of the new product. If a company is filing to revise or adjust an existing rate but lacks actuarially credible experience for the District, then the company may use countrywide experience to supplement any of their District experience.
Regardless of whether a filing is a new or introductory rate filing, or a revision to an existing rate, all companies must adequately explain why their experience for the District is not actuarially credible and how the experience they are using in place or as a supplement to their District experience is an appropriate substitute to support the rate filing.
For the purposes of this section, and "introductory rate filing" shall mean an initial rate filing by a company that has not written medical malpractice liability insurance in the District, either directly or through an affiliate, within the past five-years (5) of the filing at issue. All other rate filings will be considered revisions or adjustments unless the Commissioner, upon request, expressly deems a filing to be an "introductory rate filing."
D.C. Mun. Regs. tit. 26, r. 26-A5305