The Washington State Health Care Authority (HCA) has provided clarification for submitting Ambulatory Surgery Center (ASC) claims in ProviderOne (P1).
HCA requirement
- All ASC claims are submitted as professional claims (J claim type). These claims convert in P1 to ASC facility claims (A claim type) only when an ASC taxonomy is included on the claim.
- ASC taxonomy 261QA1903X is required. If the taxonomy is not included on the claim, then the claim will remain classified as a professional claim rather than converting to an ASC facility claim.
- In addition, use modifier SG to indicate an ASC facility claim.
CHPW claims processing
Beginning May 2026, if ASC taxonomy 261QA1903X is not included on the claim, then the claim will be denied using message code CDTAX, “Taxonomy not appropriate for billed services per contract.”
More information
Please see the HCA’s ASC billing guide for more information.
If you have any questions, please contact our Customer Service team at 1-800-440-1561.
