What is William Duan's NPI number?

William Duan's National Provider Identifier (NPI) is 1881334308, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.

What is William Duan's specialty?

William Duan is listed in the NPPES registry with a primary specialty of Psychiatric Hospital Unit (Hospital Units).

Where is William Duan located?

William Duan's practice location on file with NPPES is 1800 N California St, Stockton, CA 95204-6019.

What is William Duan's phone number?

The practice phone number listed in the NPPES registry for William Duan is (209) 547-5716.

Is William Duan's NPI active?

Yes — William Duan's NPI (1881334308) is active in the NPPES registry as of the last update on 2026-04-24.

IndividualActive

William Duan, MD

NPI 1881334308 · Psychiatric Hospital Unit · Stockton, CA

William Duan, MD is a Psychiatric Hospital Unit provider in Stockton, CA (NPI 1881334308).

Provider details

NPI number: 1881334308
Entity type: Individual
Primary specialty: Psychiatric Hospital UnitHospital Units
Credential: MD
Sex: Male
Sole proprietor: No
License: A189333 (CA)

Specialties & taxonomies

Psychiatric Hospital UnitPrimary273R00000XLicense A189333 (CA)
Hospital Units

Profile Score

Established profile(60/100 index)

A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.

Registry tenure38% of score
4 yrs in NPPES registry
Profile completeness38% of score
100% of core fields populated
Practice footprint23% of score
1 documented practice location

Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.

Practice location

1800 N California St

Stockton, CA 95204-6019

Phone: (209) 547-5716

Street-level locationGet directions

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Mailing address