Catherine Dieffenbach, MD
NPI 1861810673 · Obstetrics & Gynecology Physician · San Diego, CA
Enrolled with Medicare as Practitioner - Obstetrics/Gynecology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Catherine Dieffenbach, MD is a Obstetrics & Gynecology Physician provider in San Diego, CA (NPI 1861810673).
Provider details
- NPI number
- 1861810673
- Entity type
- Individual
- Primary specialty
- Obstetrics & Gynecology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- C187220 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
12 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
111 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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 Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 31 | $97 |
| Cervical Or Vaginal Cancer Screening; Pelvic and Clinical Breast ExaminationG0101 | 17 | $42 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 15 | $137 |
| Ultrasound Scan of Uterus, Ovaries, Tubes, Cervix and Pelvic Area Through Vagina76830 | 14 | $135 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 12 | $119 |
| Screening 3d Breast Mammography77063 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$120 across 5 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2014-03-31
- Last updated
- 2024-04-16
- Certified
- 2024-04-16
Frequently asked questions
- What is Catherine Dieffenbach's NPI number?
- Catherine Dieffenbach's National Provider Identifier (NPI) is 1861810673, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Catherine Dieffenbach's specialty?
- Catherine Dieffenbach is listed in the NPPES registry with a primary specialty of Obstetrics & Gynecology Physician (Allopathic & Osteopathic Physicians).
- Where is Catherine Dieffenbach located?
- Catherine Dieffenbach's practice location on file with NPPES is 9339 Genesee Avenue, San Diego, CA 92121-2196.
- What is Catherine Dieffenbach's phone number?
- The practice phone number listed in the NPPES registry for Catherine Dieffenbach is (858) 455-7520.
- Does Catherine Dieffenbach accept Medicare?
- Catherine Dieffenbach is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Catherine Dieffenbach's NPI active?
- Yes — Catherine Dieffenbach's NPI (1861810673) is active in the NPPES registry as of the last update on 2024-04-16.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.