Timothy J. Ernst, M.D.
Medical Oncology Physician · Natick, MA
Timothy J. Ernst, M.D. is a medical oncology physician with a practice address in Natick, Massachusetts, and NPI 1972542975, issued on Jun 5, 2006. Check the license (Massachusetts 52630, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Timothy J. Ernst
- Credential
- M.D.
- Primary taxonomy
- Medical Oncology Physician 207RX0202X
- License number
- 52630 MA
Self-reported in NPPES; status is on the state search - Practice location
- 67 Union St, Natick, MA 01760
- Phone
- (508) 655-0065
- Enumerated
- Jun 5, 2006
- Record last updated
- Jun 13, 2012 (not updated in 14 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
8 nearest medical oncology physician records → All 421 in Massachusetts → Look up another NPI →
Also registered at 67 Union St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Johanne Agne, NPAdult Health Nurse Practitioner1710022496
- Susan Almy, NPNurse Practitioner1598945594
- Lisa Ayles, ATCAthletic Trainer1508827957
- Stephen Belmonte, M.D.Ophthalmology Physician1942249834
- Robert Berkowitz, M.D.Psychiatry Physician1538183504
- Kristen Bernstein, NPFamily Nurse Practitioner1205948676
Verify Timothy J. Ernst in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 52630Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
71% fewer Medicare Part D claims than the average medical oncology physician in 2024
201 Medicare Part D claims for 56 beneficiaries, against an average of 703 among the 4,230 providers of this specialty who prescribed in Part D. Brand-name drugs were 57% of claims.
Most prescribed
- Eliquis53 claims
- Hydroxyurea33 claims
- Xarelto17 claims
- Calquence11 claims
- Promacta11 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.
Timothy J. Ernst among 421 medical oncology physician records in Massachusetts
Timothy J. Ernst, M.D. is one of 421 medical oncology physician records with a practice address in Massachusetts. 76% 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 10% of them.
- NPI issued2006 · 10% of these records are older, 60% newer
- In a Medicare fileYes · 76% of these records are
- In the CMS Doctors and Clinicians fileNo · 69% of these records are
- Record last updated2012 · 51% 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 Massachusetts 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 Massachusetts
There are 421 medical oncology physician records in Massachusetts.
All 421 in Massachusetts → Every provider in Natick → Medical Oncology Physician nationwide →
The 8 medical oncology physician records with the nearest ZIP codes
- Daniel Fein, M.D.Milford, MA 017571053791707
- Alexei Shimanovsky, M.D.,Milford, MA 017571699054924
- Charles Rosenbaum, M.D.Marlborough, MA 017521922049147
- William Slichenmyer, M.D.Sherborn, MA 017701962773424
- Kimberly Brennan, D.O.Concord, MA 017421487838744
- Russell Baur, MDBurlington, MA 018051508020470
- Sunil Bhatt, MDBurlington, MA 018051073178737
- Ragisha Gopalakrishnan, M.D.Burlington, MA 018051538502620
Common questions
What is Timothy J. Ernst, M.D.'s NPI number?
Timothy J. Ernst, M.D.'s National Provider Identifier (NPI) is 1972542975, issued on Jun 5, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Timothy J. Ernst, M.D. located?
The NPPES record lists a practice address at 67 Union St, Natick, MA, 01760. Phone: (508) 655-0065. Providers update this record themselves, so call before visiting.
How can I verify Timothy J. Ernst, M.D.'s license?
NPPES lists Massachusetts license number 52630, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Timothy J. Ernst, M.D. prescribe under Medicare Part D?
In 2024, Timothy J. Ernst, M.D. had 201 Medicare Part D claims for 56 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.