William K. Oh, M.D.
Medical Oncology Physician · Greenwich, CT
William K. Oh, M.D. is a medical oncology physician with a practice address in Greenwich, Connecticut, and NPI 1225095581, issued on Apr 28, 2006. Check the license (Connecticut 79833, as entered in NPPES) on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- William K. Oh
- Credential
- M.D.
- Primary taxonomy
- Medical Oncology Physician 207RX0202X
- License numbers
- 79833 CT
255056 NY
Self-reported in NPPES; status is on the state search - Practice location
- 77 Lafayette PL, Greenwich, CT 06830
- Phone
- (203) 863-3700
- Enumerated
- Apr 28, 2006
- Record last updated
- Dec 11, 2024
- Medicare enrollment
- Enrolled (PECOS I20250213003743); may accept Medicare assignment
- Medical or professional school
- New York University School Of Medicine, 1992
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest medical oncology physician records → All 99 in Connecticut → Look up another NPI →
Also registered at 77 Lafayette PL
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Christina Delpin, MDSurgery Physician1013920172
- Mary Beth Downer, P.A.Physician Assistant1164443032
- Beverly Drucker, MDMedical Oncology Physician1104834704
- Julie Gold, M.D.Hematology & Oncology Physician1992739742
- Suma Gupta, APRNNurse Practitioner1063206027
- Dickerman Hollister, MDMedical Oncology Physician1063420669
Verify William K. Oh in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersConnecticut Medical Examining Board
Search for license 79833Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
81% fewer Medicare Part D claims than the average medical oncology physician in 2024
133 Medicare Part D claims for 31 beneficiaries, against an average of 703 among the 4,230 providers of this specialty who prescribed in Part D. Brand-name drugs were 31% of claims.
Most prescribed
- Nubeqa26 claims
- Tamsulosin Hcl12 claims
- Venlafaxine Hcl Er12 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.
Industry payments in 2024: $27,495.88
13 payments; by number, the most common kind was food and beverage; the largest payer was Abbott Laboratories. The 3,343 providers of this specialty with any payment received $11,773.47 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through 2 group practices
- Select PT, OT And Slp Rehabilitation NY, PLLCHudson, NY
- Yale UniversityNew Haven, CT
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William K. Oh among 99 medical oncology physician records in Connecticut
William K. Oh, M.D. is one of 99 medical oncology physician records with a practice address in Connecticut. 73% 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 19% of them.
- NPI issued2006 · 19% of these records are older, 52% newer
- In a Medicare fileYes · 73% of these records are
- In the CMS Doctors and Clinicians fileYes · 67% of these records are
- Graduated1992 · median 2005 among the 66 with a school on file
- Record last updated2024 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RX0202X and a Connecticut practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Medical Oncology Physician providers in Connecticut
There are 99 medical oncology physician records in Connecticut.
All 99 in Connecticut → Every provider in Greenwich → Medical Oncology Physician nationwide →
The 8 medical oncology physician records with the nearest ZIP codes
- Beverly Drucker, MDGreenwich, CT 068301104834704
- Dickerman Hollister, MDGreenwich, CT 068301063420669
- Merlin Lee, MDGreenwich, CT 068301730292608
- Tara Sanft, M.D.Fairfield, CT 068241730374562
- Anthony Coscia, MDNorwalk, CT 068511689666372
- Kesav Nair, M.D.Norwalk, CT 068511104811132
- Rosemary Mazanet, MDCos Cob, CT 068071477988764
- Jedd Levine, M.D.Torrington, CT 067901376578054
Common questions
What is William K. Oh, M.D.'s NPI number?
William K. Oh, M.D.'s National Provider Identifier (NPI) is 1225095581, issued on Apr 28, 2006. An NPI identifies a provider in billing; it is not a license.
Where is William K. Oh, M.D. located?
The NPPES record lists a practice address at 77 Lafayette PL, Greenwich, CT, 06830. Phone: (203) 863-3700. Providers update this record themselves, so call before visiting.
How can I verify William K. Oh, M.D.'s license?
NPPES lists Connecticut license number 79833, as entered by the provider. Search the Connecticut Medical Examining Board at https://www.elicense.ct.gov/Lookup/LicenseLookup.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William K. Oh, M.D. prescribe under Medicare Part D?
In 2024, William K. Oh, M.D. had 133 Medicare Part D claims for 31 beneficiaries; the average among medical oncology physician prescribers was 703. 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.