NPPES file of Aug 9, 2026

Karbo A. Tam, M.D.

Obstetrics & Gynecology Physician · Oakland, CA

Karbo A. Tam, M.D. is an obstetrics & gynecology physician with a practice address in Oakland, California, and NPI 1659553410, issued on Dec 3, 2007. Check the license (California A101595, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1659553410
Name
Karbo A. Tam
Credential
M.D.
Primary taxonomy
Obstetrics & Gynecology Physician 207V00000X
License number
A101595 CA
Self-reported in NPPES; status is on the state search
Practice location
3451 E 12TH St, Oakland, CA 94601
Phone
(510) 535-4000
Enumerated
Dec 3, 2007
Record last updated
Dec 15, 2021 (not updated in 5 years: call before relying on the address or phone)
Fax
(510) 535-4128
Medicare enrollment
Enrolled (PECOS I20101013000206); accepts Medicare assignment
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 3451 E 12TH St

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Patricia ArteagaRegistered Nurse1619323870
  2. Melissa Ayres, MPH, RDNRegistered Dietitian1144067067
  3. Lidia Barajas Gonzalez, RNRegistered Nurse1780130450
  4. Paul Bayard, MDFamily Medicine Physician1922101237
  5. Shelli Bein, MDPediatrics Physician1982836078
  6. Julia Bley, MDObstetrics & Gynecology Physician1831357177

Verify Karbo A. Tam in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A101595
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the California license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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58% fewer Medicare Part D claims than the average obstetrics & gynecology physician in 2024

70 Medicare Part D claims for 30 beneficiaries, against an average of 165 among the 28,733 providers of this specialty who prescribed in Part D.

  1. Karbo Tam70
  2. Specialty average165

Most prescribed

  1. Estradiol13 claims

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

Bills Medicare through one group practice

  1. Permanente Medical Group IncVallejo, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Karbo A. Tam among 5,088 obstetrics & gynecology physician records in California

Karbo A. Tam, M.D. is one of 5,088 obstetrics & gynecology physician records with a practice address in California. 74% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 48% of them.

  • NPI issued2007 · 48% of these records are older, 38% newer
  • In a Medicare fileYes · 74% of these records are
  • In the CMS Doctors and Clinicians fileYes · 53% of these records are
  • Graduated2006 · median 2004 among the 2,700 with a school on file
  • Record last updated2021 · 64% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207V00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Obstetrics & Gynecology Physician providers in California

There are 5,088 obstetrics & gynecology physician records in California.

The 8 obstetrics & gynecology physician records with the nearest ZIP codes

  1. Julia Bley, MDOakland, CA 946011831357177
  2. Hilary Eggers, MDOakland, CA 946011770089591
  3. Sara Johnson, M.D.Oakland, CA 946011811125016
  4. Thuy Le, MDOakland, CA 946011831551910
  5. Stacy Paar, MDOakland, CA 946011871086017
  6. Elena Siani, MDOakland, CA 946011598299299
  7. Susan Sykes, MDOakland, CA 946011326182957
  8. Samantha Varner, MDOakland, CA 946011982059077

Common questions

What is Karbo A. Tam, M.D.'s NPI number?

Karbo A. Tam, M.D.'s National Provider Identifier (NPI) is 1659553410, issued on Dec 3, 2007. An NPI identifies a provider in billing; it is not a license.

Where is Karbo A. Tam, M.D. located?

The NPPES record lists a practice address at 3451 E 12TH St, Oakland, CA, 94601. Phone: (510) 535-4000. Providers update this record themselves, so call before visiting.

How can I verify Karbo A. Tam, M.D.'s license?

NPPES lists California license number A101595, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

How much does Karbo A. Tam, M.D. prescribe under Medicare Part D?

In 2024, Karbo A. Tam, M.D. had 70 Medicare Part D claims for 30 beneficiaries; the average among obstetrics & gynecology physician prescribers was 165. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.