Karen Callen, M.D.
NPI 1952459349 · Specialist · San Francisco, CA
Enrolled with Medicare as Practitioner - Obstetrics/Gynecology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Karen Callen, M.D. is a Specialist provider in San Francisco, CA (NPI 1952459349).
Provider details
- NPI number
- 1952459349
- Entity type
- Individual
- Primary specialty
- SpecialistOther Service Providers
- Credential
- M.D.
- Sex
- Female
- Sole proprietor
- No
- License
- A42176 (CA)
Specialties & taxonomies
Other Service Providers
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 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
107 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) |
|---|---|---|
| Cervical Or Vaginal Cancer Screening; Pelvic and Clinical Breast ExaminationG0101 | 72 | $45 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 22 | $99 |
| Screening Papanicolaou Smear; Obtaining, Preparing and Conveyance of Cervical Or Vaginal Smear to LaboratoryQ0091 | 13 | $54 |
Typical Medicare-allowed amounts for these services range $45–$99 (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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 9 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Estradiol | 89 | 34 |
| Progesterone, Micronizedbrand: Progesterone | 48 | 14 |
| Estradiolbrand: Estradiol (twice Weekly) | 33 | 12 |
| Valacyclovir Hclbrand: Valacyclovir | 29 | 11 |
| Escitalopram Oxalate | 14 | — |
| Estrogens, Conjugatedbrand: Premarin | 14 | — |
| Raloxifene Hcl | 14 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$507 across 20 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
- 2007-01-08
- Last updated
- 2019-08-27
Frequently asked questions
- What is Karen Callen's NPI number?
- Karen Callen's National Provider Identifier (NPI) is 1952459349, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Karen Callen's specialty?
- Karen Callen is listed in the NPPES registry with a primary specialty of Specialist (Other Service Providers).
- Where is Karen Callen located?
- Karen Callen's practice location on file with NPPES is 1725 Montgomery St, San Francisco, CA 94111-1030.
- What is Karen Callen's phone number?
- The practice phone number listed in the NPPES registry for Karen Callen is (415) 831-2180.
- Does Karen Callen accept Medicare?
- Karen Callen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Karen Callen's NPI active?
- Yes — Karen Callen's NPI (1952459349) is active in the NPPES registry as of the last update on 2019-08-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.