The Washington State Department of Social and Health Services, Behavioral Health Administration, Office of Forensic Mental Health Services Trueblood et al v. Washington State DSHS page links the Trueblood Implementation Plan, in which phased implementation regions are identified. The plan notes that the implementation regions are based on the Washington State Managed Care Organizations (MCO) and Administrative Service Organizations (ASO) regions. Further investigation reveals that both of these types of regions are based on Washington State Health Care Authority Integrated Managed Care Regions, which are in turn composed of Washington State County boundaries.
Accuracy note - The Trueblood Implementation Regions boundaries are derived from 2010 US Census County boundaries. These boundaries are known to have significant discrepancies with survey-quality county boundary data available from Washington State Department of Natural Resources. Therefore, care should be taken to avoid making any final determinations regarding the Trueblood Implementation Region in which is located a high-accuracy feature such as a physical address when it is near a region boundary.
Important: DSHS reserves the right to alter, suspend, re-host, or retire this service at any time and without notice. This is a map service that you can use in custom web applications and software products. Your use of this map service in these types of tools forms a dependency on the service definition (available fields, layers, etc.). If you form any dependency on this service, be aware of this significant risk to your purposes. You might consider mitigating your risk by extracting the source data and using it to host your own service in an environment under your control. Typically, DSHS Enterprise GIS staff will provide notification of changes via the Comments RSS capability in ArcGIS Online. You should subscribe to this RSS feed to monitor change notifications: https://www.arcgis.com/sharing/rest/content/items/585bca49c0614b75a2dbc28f8d4f5079/comments?f=rss