Cornelius Jansen, MD
NPI 1285712380 · Otolaryngology Physician · Walnut Creek, CA
Enrolled with Medicare as Practitioner - Otolaryngology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Cornelius Jansen, MD is a Otolaryngology Physician provider in Walnut Creek, CA (NPI 1285712380).
Provider details
- NPI number
- 1285712380
- Entity type
- Individual
- Primary specialty
- Otolaryngology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G85048 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
70 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. 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.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 33 | $136 |
| Removal of Impacted Ear Wax69210 | 19 | $51 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 18 | $176 |
Typical Medicare-allowed amounts for these services range $51–$176 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-11-02
- Last updated
- 2019-10-11
Frequently asked questions
- What is Cornelius Jansen's NPI number?
- Cornelius Jansen's National Provider Identifier (NPI) is 1285712380, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Cornelius Jansen's specialty?
- Cornelius Jansen is listed in the NPPES registry with a primary specialty of Otolaryngology Physician (Allopathic & Osteopathic Physicians).
- Where is Cornelius Jansen located?
- Cornelius Jansen's practice location on file with NPPES is 1425 S Main St, Walnut Creek, CA 94596-5318.
- What is Cornelius Jansen's phone number?
- The practice phone number listed in the NPPES registry for Cornelius Jansen is (925) 295-4000.
- Does Cornelius Jansen accept Medicare?
- Cornelius Jansen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Cornelius Jansen's NPI active?
- Yes — Cornelius Jansen's NPI (1285712380) is active in the NPPES registry as of the last update on 2019-10-11.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.