Companion Guides

For easy reference BHT is collecting Companion Guides from each of the managed care organizations (MCOs) in our region onto this page. Stay tuned for more updates.

Community Health Plan of Washington (CHPW)

For Providers (not the BHASO’s), CHPW strictly follows the 837 Healthcare Claim Professional and Institutional Guide (IG) version 5010, SERI for substance use disorder providers, and the HCA guidelines. Because we follow these we do not have CHPW specific companion guides.

  1. The 837 Healthcare Claim Professional Guide (IG) version 5010 can be found at or by calling (425) 562-2245.
  2. Service Encounter Reporting Instructions (SERI)
  3. The HCA guidelines are at

The acknowledgement files (999/277CA) are discussed in the 837 transaction companion guide.

For the BHASO’s we also have the below encounter information in addition to the above: