What is Walter Callen's NPI number?

Walter Callen's National Provider Identifier (NPI) is 1972451854, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.

What is Walter Callen's specialty?

Walter Callen is listed in the NPPES registry with a primary specialty of Peer Specialist (Other Service Providers).

Where is Walter Callen located?

Walter Callen's practice location on file with NPPES is 9410 Macarthur Blvd Apt 301, Oakland, CA 94605-4738.

What is Walter Callen's phone number?

The practice phone number listed in the NPPES registry for Walter Callen is (510) 372-7464.

Is Walter Callen's NPI active?

Yes — Walter Callen's NPI (1972451854) is active in the NPPES registry as of the last update on 2026-03-17.

IndividualActive

Walter Callen

NPI 1972451854 · Peer Specialist · Oakland, CA

Walter Callen is a Peer Specialist provider in Oakland, CA (NPI 1972451854).

Provider details

NPI number: 1972451854
Entity type: Individual
Primary specialty: Peer SpecialistOther Service Providers
Sex: Male
Sole proprietor: Yes
License: 735367 (CA)

Specialties & taxonomies

Peer SpecialistPrimary175T00000XLicense 164X000000X
Other Service Providers
Licensed Vocational Nurse164X00000XLicense 735367 (CA)
Nursing Service Providers

Profile Score

Established profile(53/100 index)

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

Registry tenure38% of score
Under 1 yr in 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

9410 Macarthur Blvd Apt 301

Oakland, CA 94605-4738

Phone: (510) 372-7464

Street-level locationGet directions

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Mailing address