DR. KAREN CALLEN M.D.
NPI 1952459349
Specialist in San Francisco, CA

Q: What is Karen Callen's NPI number?

The NPI number for Karen Callen is 1952459349. It was assigned to this individual provider in the NPPES registry on January 8, 2007.

Q: What is Karen Callen's specialty?

The primary specialty registered for this NPI is Specialist with taxonomy code 174400000X.

Q: When was this NPI record last updated?

The NPPES record for Karen Callen was last updated on August 27, 2019. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since January 08, 2007PECOS Enrolled

1725 MONTGOMERY ST, SUITE 200, SAN FRANCISCO, CA 94111(415) 831-2180(415) 668-6970 Get Directions Write a Review

NPPES record last updated: August 27, 2019. Verified against the NPPES registry weekly; last sync: October 18, 2026.

On this page

About Dr. Karen Callen M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. KAREN CALLEN M.D. (NPI 1952459349) is an individual specialist in San Francisco, California, licensed in California (A42176) and active in the NPI registry since January 2007. She is enrolled in Medicare PECOS and is a graduate of Tulane University School Of Medicine (1984).

NPPES Registry Identity

NPI1952459349

Entity TypeIndividualFemale

Primary Taxonomy174400000X

Provider Legal NameDR. KAREN CALLENCredential: M.D.

Location Address1725 MONTGOMERY ST, SUITE 200San Francisco, CA 94111-1030

Mailing Address1725 Montgomery St, Suite 200San Francisco, CA 94111-1030 · (415) 831-2180 · Fax (415) 668-6970

Phone(415) 831-2180

Fax(415) 668-6970

Sole ProprietorNo

Medical School CMSTulane University School Of MedicineGraduated 1984

Enumeration DateJanuary 8, 2007

Last NPPES UpdateAugust 27, 2019

✔ NPI 1952459349 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtySpecialistOther Service Providers

Taxonomy Code174400000X

License✔ Licensed in CA · A42176

Definition

An individual educated and trained in an applied knowledge discipline used in the performance of work at a level requiring knowledge and skills beyond or apart from that provided by a general education or liberal arts degree.

Also ListedObstetrics & GynecologyTaxonomy 207V00000X · License A42176 (CA)

1725 MONTGOMERY ST, San Francisco, CA 94111

Open in Google Maps ↗

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Karen Callen M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

PECOS PAC ID9931237492

PECOS Enrollment IDI20101221000936

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

Medicare enrollment records show Karen Callen reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

University Of California San Francisco

4.0 mi

Surgery

400 PARNASSUS AVE, MCB 300
San Francisco, CA 94143

Reassigned Medicare billing, California enrollment
5,645 clinicians in this Medicare group

NPI 1346329380 (415) 353-2161

Ucsf Medical Group Business Services

4.0 mi

Internal Medicine

400 PARNASSUS AVE
San Francisco, CA 94122

Reassigned Medicare billing, California enrollment
5,544 clinicians in this Medicare group

NPI 1477624104 (415) 353-2808

Regents Univ Of California Ucsf

4.1 mi

Internal Medicine

505 PARNASSUS AVE
San Francisco, CA 94143

Reassigned Medicare billing, California enrollment
339 clinicians in this Medicare group

NPI 1124439807 (415) 476-1000

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 3

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Cervical or vaginal cancer screening; pelvic and clinical breast examination G0101

This procedure involves checking for health issues in the lower abdomen and chest area. It helps identify early signs of certain conditions, increasing the chance for successful treatment. It's a routine check-up that's important for maintaining good health.

72 services72 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

22 services20 patients

Screening papanicolaou smear; obtaining, preparing and conveyance of cervical or vaginal smear to laboratory Q0091

A Papanicolaou smear, often called a Pap smear, is a test to check for changes in cells. A small sample is gently collected from the lower region and sent to a lab for examination. This helps in early detection of potential health issues.

13 services13 patients

Other Providers at the Same Location NPPES 6

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. FUNG LAM M.D.

Specialist

1725 MONTGOMERY ST, SUITE #200
SAN FRANCISCO, CA 94111

San Francisco County (415) 831-2180

GOLDEN GATE OBSTETRICS & GYNECOLOGY INC A MEDICAL CORPORATION

Specialist

1725 MONTGOMERY ST, SUITE 200
SAN FRANCISCO, CA 94111

San Francisco County (415) 666-1250

DR. JANE FANG M.D.

Specialist

1725 MONTGOMERY ST, SUITE #200
SAN FRANCISCO, CA 94111

San Francisco County (415) 666-1250

LESLEY M MEISTER MD

Obstetrics & Gynecology

1725 MONTGOMERY ST, SUITE 200
SAN FRANCISCO, CA 94111

San Francisco County (415) 666-1250

MRS. HILLARY MILLS NP-C

Nurse Practitioner (Family)

1725 MONTGOMERY ST, #200
SAN FRANCISCO, CA 94111

San Francisco County (415) 666-1250

MILANA LUISA BERGUIG MD

Obstetrics & Gynecology

1725 MONTGOMERY ST, SUITE 200
SAN FRANCISCO, CA 94111

San Francisco County (415) 666-1250

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Karen Callen's NPI number?

The NPI number for Karen Callen is 1952459349. It was assigned to this individual provider in the NPPES registry on January 8, 2007.

Where is Karen Callen located?

Karen Callen practices at 1725 Montgomery St Suite 200, San Francisco, CA 94111. The listed phone number is (415) 831-2180.

What is Karen Callen's specialty?

The primary specialty registered for this NPI is Specialist with taxonomy code 174400000X.

Is Karen Callen enrolled in Medicare?

Yes. Karen Callen is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Karen Callen's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Karen Callen reassigns Medicare benefits to 3 organizations: University Of California San Francisco (San Francisco, CA), Ucsf Medical Group Business Services (San Francisco, CA) and Regents Univ Of California Ucsf (San Francisco, CA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Karen Callen's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Karen Callen was last updated on August 27, 2019. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.