The large employer group health insurance market lacks a standardized source for nationwide premium development information. California regulations require issuers of these health insurance products to submit rate filings to their regulators. This white paper summarizes key statistics from six years of these filings. California enacted Assembly Bill 731 (AB 731) to regulate large employer group health insurance premiums in the state. AB 731 requires carriers to submit annual rate filings to the Department of Managed Health Care (DMHC) and the California Department of Insurance. The first rate filing was for large group plans with effective dates in calendar year 2021. The bill is in line with the DMHC’s mission to protect healthcare consumers and ensure a stable healthcare delivery system, and it aims to help the DMHC determine whether a large group rate filing is reasonable. With their filings, large group issuers are required to disclose experience period claims, methodologies, factors, and assumptions that were used to set projected premium rates, which DMHC accomplishes annually through a standard rate filing template and supplemental filing documents. Our analysis covers the following filing results:
- Summary of 2026 premium information by product type: Health maintenance organization, preferred provider organization, and high-deductible health plan, and other
- Experience period costs: Claims distribution and loss ratios by experience year, and allowed costs as a percentage of Medicare by experience year
- Projected allowed costs and trends for per member per month by region, and 2026 statewide allowed trends