Karen J. Sumner, MD
Obstetrics & Gynecology Physician · Oakland, CA
Karen J. Sumner, MD is an obstetrics & gynecology physician with a practice address in Oakland, California, and NPI 1740360205, issued on Oct 17, 2006. Check the license (California C55246, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Karen J. Sumner
- Credential
- MD
- Primary taxonomy
- Obstetrics & Gynecology Physician 207V00000X
- License number
- C55246 CA
Self-reported in NPPES; status is on the state search - Practice location
- 275 W Macarthur Blvd, Oakland, CA 94611
- Phone
- (510) 752-1000
- Enumerated
- Oct 17, 2006
- Record last updated
- Dec 22, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20121129000401); accepts Medicare assignment
- Medical or professional school
- Rutgers New Jersey Medical School, 1995
- Entity
- Type 1 · individual
8 nearest obstetrics & gynecology physician records → All 5,088 in California → Look up another NPI →
Also registered at 275 W Macarthur Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Brett Adams, MDStudent in an Organized Health Care Education/Training Program1841731098
Verify Karen J. Sumner in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license C55246Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2.4 times the Medicare Part D claims of the average obstetrics & gynecology physician in 2024
403 Medicare Part D claims for 162 beneficiaries, against an average of 165 among the 28,733 providers of this specialty who prescribed in Part D. Brand-name drugs were 19% of claims.
Most prescribed
- Estradiol121 claims
- Estring46 claims
- Yuvafem36 claims
- Progesterone30 claims
- Acyclovir20 claims
- Climara16 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
- Permanente Medical Group IncRichmond, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Karen J. Sumner among 5,088 obstetrics & gynecology physician records in California
Karen J. Sumner, MD 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 2006, is newer than 5% of them.
- NPI issued2006 · 5% of these records are older, 52% newer
- In a Medicare fileYes · 74% of these records are
- In the CMS Doctors and Clinicians fileYes · 53% of these records are
- Graduated1995 · 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.
All 5,088 in California → Every provider in Oakland → Obstetrics & Gynecology Physician nationwide →
The 8 obstetrics & gynecology physician records with the nearest ZIP codes
- Grace Cavallaro, MDOakland, CA 946111548342165
- Victor Chin, MDOakland, CA 946111598843385
- Christie Cooksey, MDOakland, CA 946111689668386
- Patrick Dawkins, MDOakland, CA 946111760571145
- Rima Goldman, MDOakland, CA 946111528146354
- Judith Lamberti, MDOakland, CA 946111043398837
- Susan Liu, MDOakland, CA 946111376629881
- Sonia Ordonez, MDOakland, CA 946111215049986
Common questions
What is Karen J. Sumner, MD's NPI number?
Karen J. Sumner, MD's National Provider Identifier (NPI) is 1740360205, issued on Oct 17, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Karen J. Sumner, MD located?
The NPPES record lists a practice address at 275 W Macarthur Blvd, Oakland, CA, 94611. Phone: (510) 752-1000. Providers update this record themselves, so call before visiting.
How can I verify Karen J. Sumner, MD's license?
NPPES lists California license number C55246, 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 Karen J. Sumner, MD prescribe under Medicare Part D?
In 2024, Karen J. Sumner, MD had 403 Medicare Part D claims for 162 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.