Walter C. Prehn M.D. a Professional Corporation
NPI 1306143169 · Internal Medicine Physician · Sonoma, CA
Walter C. Prehn M.D. a Professional Corporation is a Internal Medicine Physician organization in Sonoma, CA (NPI 1306143169).
Provider details
- NPI number
- 1306143169
- Entity type
- Organization
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Organization subpart
- No
- Authorized official
- Walter Prehn, President(707) 495-7762
- License
- G25454 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
15 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
Mailing address
Registry dates
- Enumerated
- 2011-02-14
- Last updated
- 2012-10-05
Frequently asked questions
- What is Walter C. Prehn M.D. a Professional Corporation's NPI number?
- Walter C. Prehn M.D. a Professional Corporation's National Provider Identifier (NPI) is 1306143169, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What type of organization is Walter C. Prehn M.D. a Professional Corporation?
- Walter C. Prehn M.D. a Professional Corporation is classified in the NPPES registry as Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Walter C. Prehn M.D. a Professional Corporation located?
- Walter C. Prehn M.D. a Professional Corporation's practice location on file with NPPES is 181 Andrieux St, Sonoma, CA 95476-6920.
- What is Walter C. Prehn M.D. a Professional Corporation's phone number?
- The practice phone number listed in the NPPES registry for Walter C. Prehn M.D. a Professional Corporation is (707) 495-7762.
- Who is the authorized official for Walter C. Prehn M.D. a Professional Corporation?
- The authorized official listed on Walter C. Prehn M.D. a Professional Corporation's NPPES record is Walter Prehn, President. The authorized official registers and maintains the organization's NPI and is not necessarily its owner.
- Is Walter C. Prehn M.D. a Professional Corporation's NPI active?
- Yes — Walter C. Prehn M.D. a Professional Corporation's NPI (1306143169) is active in the NPPES registry as of the last update on 2012-10-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.