John Gruen, M.D.
NPI 1194769570 · Neurological Surgery Physician · Los Angeles, CA
Enrolled with Medicare as Practitioner - Neurosurgery · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Gruen, M.D. is a Neurological Surgery Physician provider in Los Angeles, CA (NPI 1194769570).
Provider details
- NPI number
- 1194769570
- Entity type
- Individual
- Primary specialty
- Neurological Surgery PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- G63324 (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
20 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
- 2006-06-15
- Last updated
- 2023-11-27
- Certified
- 2020-08-31
Frequently asked questions
- What is John Gruen's NPI number?
- John Gruen's National Provider Identifier (NPI) is 1194769570, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Gruen's specialty?
- John Gruen is listed in the NPPES registry with a primary specialty of Neurological Surgery Physician (Allopathic & Osteopathic Physicians).
- Where is John Gruen located?
- John Gruen's practice location on file with NPPES is 1520 San Pablo St, Los Angeles, CA 90033-5310.
- What is John Gruen's phone number?
- The practice phone number listed in the NPPES registry for John Gruen is (323) 442-5720.
- Does John Gruen accept Medicare?
- John Gruen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Gruen's NPI active?
- Yes — John Gruen's NPI (1194769570) is active in the NPPES registry as of the last update on 2023-11-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.