NPI registry status
Active
2026 NPPES data Medical Oncology Physician NPI 1972542975 M.D.
Verify on CMS → Timothy Ernst, M.D.
Medical Oncology Physician in Natick, Massachusetts.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 3,815 in Medical Oncology Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
136
Medicare Part D claims · 47 beneficiaries · Medical Oncology Physician avg: 689
Generic prescribing
49%
generic claims · 51% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Timothy Ernst, M.D. filed 136 Medicare Part D claims in 2023 as a Medical Oncology Physician in Natick, Massachusetts, prescribing 49% generic.
- 136
- Part D claims, 2023
- 49%
- generic prescribing
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
Timothy Ernst, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
136 35th percentile higher than 35% of 1,370,886 prescribers
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Medicare Part D Prescriber Public Use File · 2023
◑
Board-eligible specialty (heuristic, not verified)
Timothy Ernst, M.D. practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Timothy Ernst, M.D.?
Quality data not reportedPrimary specialty
Medical Oncology Physician
Medicare Part D claims
136 80% vs specialty avg
Specialty distribution in Massachusetts
How Medical Oncology Physician compares to other specialties among Massachusetts providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Medical Oncology Physician. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Timothy Ernst, M.D. appears in the CMS NPPES registry as a Medical Oncology Physician provider holding M.D. credentials at 67 UNION ST, Natick, MA, 01760, with a listed phone of (508) 655-0065. NPI 1972542975 was issued on 06/05/2006.
Medicare Part D records for calendar year 2023 show 136 prescription claims written by this provider, covering 47 Medicare beneficiaries and totaling roughly $298K in drug spend, split 51% brand-name and 49% generic by claim count.
Medical Oncology Physician is a narrow specialty nationwide, with 3,815 enrolled providers across 53 states and an average of 689 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline.
Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist, always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.
Practice Address
Provider Details
| NPI | 1972542975 |
|---|---|
| Specialty | Medical Oncology Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 06/05/2006 |
License & disciplinary context - Massachusetts BORIM 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~38K Massachusetts medical licensees in 2023 - they are NOT specific to Timothy Ernst, M.D.. To verify Timothy Ernst, M.D.'s current license status, search the BORIM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
80
Total board actions, Massachusetts 2023
Across 78 cases
2.11
Actions per 1,000 licensees
Massachusetts statewide rate
probation
Most common action type
29 cases
BORIM publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Massachusetts disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Brand-heavy
Timothy Ernst, M.D. - brand share 51.0%
Medical Oncology Physician average
51% brand-name claims vs 49% generic, on 136 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
136
Total Claims
$298K
Total Drug Cost
47
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 266
- Total Day Supply
- 7,704
- Brand vs Generic
- 51% brand / 49% generic
- Brand Drug Cost
- $295K
- Generic Drug Cost
- $3K
Patient Demographics
- Average Patient Age
- 76.0 years
- Avg HCC Risk Score
- 1.61
- Gender Split
- 64% female / 36% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Timothy Ernst, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Eliquis
Eliquis
43 claims
- Hydroxyurea
Hydroxyurea
22 claims
- Abiraterone Acetate 11
Abiraterone Acetate
11 claims
| Drug | Claims |
|---|---|
| Eliquis Apixaban | 43 |
| Hydroxyurea | 22 |
| Abiraterone Acetate | 11 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Medical Oncology Physician Overview
How Timothy Ernst, M.D. fits within the Medical Oncology Physician landscape nationally.
3,815
Medical Oncology Physician Providers in US
53
States with Medical Oncology Physician
689
Avg Claims per Provider
Timothy Ernst, M.D.'s 136 claims are below the specialty average of 689.
Nearby Medical Oncology Physician Providers in Massachusetts
Other clinicians with the same primary specialty enrolled in Massachusetts, drawn from the same CMS NPPES roster as Ernst.
Dr. Janet Abrahm
MD
Boston, MA
Dr. Thomas Abrams
M.D.
Boston, MA
Dr. Jeremy Abramson
MD
Boston, MA
Dr. Adeboye Adewoye
M.D.
Boston, MA
Dr. Andrew Aguirre
MD, PHD
Boston, MA
Compare Medical Oncology Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Massachusetts medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Medical Oncology Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is Timothy Ernst, M.D.'s specialty? ▼
Timothy Ernst, M.D. specializes in Medical Oncology Physician and practices in Natick, Massachusetts. Credentials: M.D..
How much does Timothy Ernst, M.D. prescribe under Medicare Part D? ▼
In 2023, Timothy Ernst, M.D. wrote 136 Medicare Part D claims totaling $298K in drug costs for 47 beneficiaries.
Where is Timothy Ernst, M.D. located? ▼
Timothy Ernst, M.D. is located at 67 UNION ST, Natick, MA, 01760. Phone: (508) 655-0065.
What is Timothy Ernst, M.D.'s NPI number? ▼
Timothy Ernst, M.D.'s National Provider Identifier (NPI) is 1972542975, issued on 06/05/2006.
Does Timothy Ernst, M.D. prescribe more brand-name or generic drugs? ▼
Timothy Ernst, M.D.'s prescribing is 51% brand-name and 49% generic drugs by claim count, with $295K in brand drug costs.
How many Medical Oncology Physician providers are there in the US? ▼
There are 3,815 Medical Oncology Physician providers across 53 states in the US. The average Medical Oncology Physician provider writes 689 Medicare Part D claims per year.
What drugs does Timothy Ernst, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Timothy Ernst, M.D.'s most frequently prescribed drugs include Eliquis, Hydroxyurea, Abiraterone Acetate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Timothy Ernst, M.D. accept Medicare? ▼
Timothy Ernst, M.D. appears in CMS Medicare data with 136 Part D claims and 47 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Timothy Ernst, M.D.'s credentials? ▼
Timothy Ernst, M.D.'s NPI is 1972542975 with credentials M.D.. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Compiled from official public sources by the PlainDoctor editorial team.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.