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The Washington State Department of Social and Health Services (DSHS) has replaced its Medicaid Management Information System with a new payment processing system they have named ProviderOne. ProviderOne is now the primary provider payment processing system for DSHS. 

Dentists should prepare claims with the three new billing identifiers ProviderOne requires: National Provider Identifier (NPI); the new ProviderOne Client ID (replaces the client PIC); and taxonomy.

Claims sent to the Department without these new identifiers will be denied. An additional fact sheet specific to dental providers is available at

The Department also has a tip sheet for some common stumbling blocks with ProviderOne

You can reach the Department at 1-800-562-3022. For questions related to ProviderOne readiness activities (login, password, review of your provider file) use extension 19583.


The NPI number is a unique identification number mandated under the Administrative Simplification portion of HIPAA for health care providers. DSHS requires all dentists submitting electronic and paper claims to obtain an NPI. To obtain your federal NPI number, visit or call 1-800-464-3203.


A Taxonomy Code is a unique, 10-digit, alphanumeric code that allows a provider to identify its specialty category. Providers applying for an NPI will be required to submit taxonomy information. A Provider may have one or more than one taxonomy associated with it. For a provider to bill with a taxonomy code, that taxonomy code must be associated with the provider. Taxonomy codes for dentists can be found here:

ProviderOne Client ID

The ProviderOne client ID number is needed for verifying eligibility, submitting prior authorizations, and billing.  Some refer to it as the “WA” number because all IDs contain 9 numerals followed by WA.


The ProviderOne client ID number is printed on the patient’s Services Card – if they have it (it can take several days to receive after becoming eligible for services).

If you know the Personal ID Code (PIC) that was assigned to the patient in the old payment system (even if you did not bill us for the patient), DSHS has a web based tool that you can use to look up the new ProviderOne client ID.  The tool will not return eligibility or other client information. It is available at  Select “Find P1 Client ID from any PIC”.  You will need your National Provider Identifier (NPI) and tax ID to access the tool.  This tool will not work for new patients who became eligible for services after April 23, 2010, since these clients were not assigned a PIC. This is a temporary tool meant only to assist with the transition.

Use the eligibility inquiry feature in ProviderOne using the client’s name, date of birth, or social security number.