WA SB6159

Expands authority for public hospital districts (not just rural ones) to enter cooperative agreements with other public hospital districts and publicly owned health care entities on a noncompetitive basis for service allocation, joint equipment purchases, and payment contracts.

Adds public hospital districts and publicly owned health care entities as eligible "participants" under the Washington Health Care Facilities Authority, allowing them access to bond financing for health care facility projects.

Imposes a new annual assessment of $0.75 per coverage month on health insurers and health care service contractors, with the first payment due March 1, 2027.

Creates the Public Hospital Infrastructure Account in the state treasury to receive assessment revenues, which may only be used to fund major construction or modernization projects at public district hospitals or publicly owned health care entities.

Prohibits insurers from passing the assessment cost through to enrollees via premiums, rates, or plan design, with penalties of 5-20% for late payment and potential revocation of certificate of authority for delinquent insurers.