NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1942213509 MD
Verify on CMS → Gregory Johnson, MD
Internal Medicine Physician in Somerville, 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 174,792 in Internal Medicine 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
781
Medicare Part D claims · 577 beneficiaries · Internal Medicine Physician avg: 3K
What the federal data shows
Gregory Johnson, MD filed 781 Medicare Part D claims in 2024 as an Internal Medicine Physician in Somerville, Massachusetts.
- 781
- Part D claims, 2024
- Likely
- board-certified (heuristic)
- ≥70th
- pct by Part D claim volume (lower-bound band)
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.
Federal trust snapshot
What official records show about Gregory Johnson, MD
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1942213509), first enumerated 08/14/2006.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 781 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Heuristic suggests board-certified status based on ABMS-eligible specialty taxonomy plus active CMS participation signals — not a direct ABMS verification.
- Reported
Hospital affiliations
1 CMS Care Compare hospital affiliation on record — practice footprint from the Doctors and Clinicians file.
Source: CMS Care Compare
- State context
State board disciplinary context
Massachusetts statewide board action statistics are published annually — these figures describe aggregate state activity, not Gregory Johnson, MD's individual license status. Verify directly with the state medical board.
Source: BORIM annual report 2023
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1942213509 · Internal Medicine Physician
NPI-10 · ENUM-LEGACY · TAX-MEGA · RX-LIGHT · BOOK-MID · PHOTO-ENUM
- NPI-10 1942213509
- ENUM-LEGACY 2006
- TAX-MEGA 175K Internal Medicine
- RX-LIGHT 781
- BOOK-MID 7,865 in Massachusetts
- PHOTO-ENUM Mavis Matsumoto, M.D. · 2006
Gregory Johnson, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
781 ≥ 70th percentile 70% of 1,416,883 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
✓
Board certification likely (heuristic, not verified)
Gregory Johnson, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation - signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Gregory Johnson, MD?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
781 72% vs specialty avg
Specialty distribution in Massachusetts
How Internal Medicine 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 Internal Medicine 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).
Practice Address
Provider Details
| NPI | 1942213509 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 08/14/2006 |
Hospital and facility affiliations
Facilities where Gregory Johnson, MD bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" - a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.
Atrius Health Inc
Needham, MA
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
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 Gregory Johnson, MD. To verify Gregory Johnson, MD'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.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2024.
781
Total Claims
$15K
Total Drug Cost
577
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 840.1
- Total Day Supply
- 10,805
- Generic Drug Cost
- $8K
- Opioid Claims
- 22 (2.8% rate)
- Antibiotic Claims
- 310
Patient Demographics
- Average Patient Age
- 73.9 years
- Avg HCC Risk Score
- 1.24
- Gender Split
- 63% female / 37% male
- Age Distribution
- <65: 51, 65-74: 237, 75-84: 227, 85+: 62
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What Gregory Johnson, MD prescribes most
Top Medicare Part D drugs by claim count, 2024
- Doxycycline Monohy…
Doxycycline Monohydrate
67 claims
- Prednisone
Prednisone
63 claims
- Amoxicillin-Clavul…
Amoxicillin-Clavulanate Potass
45 claims
- Cephalexin
Cephalexin
32 claims
- Nitrofurantoin Mon…
Nitrofurantoin Mono-Macro
31 claims
- Cyclobenzaprine Hcl 24
Cyclobenzaprine Hcl
24 claims
- Amoxicillin 22
Amoxicillin
22 claims
- Azithromycin 22
Azithromycin
22 claims
| Drug | Claims |
|---|---|
| Doxycycline Monohydrate | 67 |
| Prednisone | 63 |
| Amoxicillin-Clavulanate Potass Amoxicillin/Potassium Clav | 45 |
| Cephalexin | 32 |
| Nitrofurantoin Mono-Macro Nitrofurantoin Monohyd/M-Cryst | 31 |
| Cyclobenzaprine Hcl | 24 |
| Amoxicillin | 22 |
| Azithromycin | 22 |
| Cefuroxime Cefuroxime Axetil | 21 |
| Sulfamethoxazole-Trimethoprim Sulfamethoxazole/Trimethoprim | 21 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Internal Medicine Physician Overview
How Gregory Johnson, MD fits within the Internal Medicine Physician landscape nationally.
174,792
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,785
Avg Claims per Provider
Gregory Johnson, MD's 781 claims are below the specialty average of 2,785.
Nationwide Internal Medicine Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Johnson, both outside Massachusetts so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2006)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Internal Medicine Physician Providers in Massachusetts
Other clinicians with the same primary specialty enrolled in Massachusetts, drawn from the same CMS NPPES roster as Johnson.
One of 7,865 Internal Medicine Physician providers enrolled in Massachusetts, 5 are shown here.
Dr. Nawal Aamir
MD
Worcester, MA
Zainab Abbas
Worcester, MA
Nooshin Abbasi
MD MPH
Newton, MA
Dr. Lauren Abbate
MD
Boston, MA
Dr. Bassima Abdallah
MD
Boston, MA
Compare Internal Medicine Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Gregory Johnson, MD's specialty? ▼
Gregory Johnson, MD specializes in Internal Medicine Physician and practices in Somerville, Massachusetts. Credentials: MD.
How much does Gregory Johnson, MD prescribe under Medicare Part D? ▼
In 2024, Gregory Johnson, MD wrote 781 Medicare Part D claims totaling $15K in drug costs for 577 beneficiaries.
Where is Gregory Johnson, MD located? ▼
Gregory Johnson, MD is located at 40 HOLLAND ST, Somerville, MA, 02144. Phone: (617) 629-6350.
What is Gregory Johnson, MD's NPI number? ▼
Gregory Johnson, MD's National Provider Identifier (NPI) is 1942213509, issued on 08/14/2006.
Does Gregory Johnson, MD prescribe opioids? ▼
Yes, Gregory Johnson, MD had 22 opioid claims in 2024 with an opioid prescribing rate of 2.8%.
How many Internal Medicine Physician providers are there in the US? ▼
There are 174,792 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,785 Medicare Part D claims per year.
What drugs does Gregory Johnson, MD prescribe most often? ▼
Based on 2024 Medicare Part D data, Gregory Johnson, MD's most frequently prescribed drugs include Doxycycline Monohydrate, Prednisone, Amoxicillin-Clavulanate Potass. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Gregory Johnson, MD accept Medicare? ▼
Gregory Johnson, MD appears in CMS Medicare data with 781 Part D claims and 577 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Gregory Johnson, MD's credentials? ▼
Gregory Johnson, MD's NPI is 1942213509 with credentials MD. 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 (2024). 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 August 2026 (NPPES) / 2024 (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
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 August 2026.