2026 NPPES data Medical Physician Assistant NPI 1821304312 PA
Verify on CMS →

PETER BUCHANAN, PA

Medical Physician Assistant in GREENFIELD, Massachusetts. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
3K
Medicare Part D claims · 400 beneficiaries · Medical Physician Assistant avg: 1K
Generic prescribing
89%
generic claims · 11% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

PETER BUCHANAN, PA filed 3,282 Medicare Part D claims in 2023 as a Medical Physician Assistant in GREENFIELD, Massachusetts, prescribing 89% generic.

3K
Part D claims, 2023
89%
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.

PETER BUCHANAN, PA's Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

3,282 Top 11% higher than 89% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

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

What does the federal data show about PETER BUCHANAN, PA?

Quality data not reported

NPI registry status

Active

Issued 08/23/2010

NPI 1821304312

Primary specialty

Medical Physician Assistant

Mid-sized

40,527 US NPIs in this specialty

Medicare Part D claims

3,282 205% vs specialty avg

2023 prescription claims

Specialty avg: 1,077

Specialty distribution in Massachusetts

How Medical Physician Assistant compares to other specialties among Massachusetts providers

Massachusetts providers

Medical Physician Assistant share within Massachusetts

1. Medical Physician Assistant42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Medical Physician Assistant share within Massachusetts

Specialty board-certification context

Estimated specialty board-certified rate — Medical Physician Assistant (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Medical Physician Assistant ABMS/AOA estimate

Est. board-certified rate (Medical Physician Assistant) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Medical Physician Assistant) — ABMS / AOA estimate

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).

PETER BUCHANAN, PA appears in the CMS NPPES registry as a Medical Physician Assistant provider holding PA credentials at 329 CONWAY ST, GREENFIELD, MA, 01301, with a listed phone of (413) 774-6301. NPI 1821304312 was issued on 08/23/2010. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what BUCHANAN most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 3,282 prescription claims written by this provider, covering 400 Medicare beneficiaries and totaling roughly $346K in drug spend, split 11% brand-name and 89% generic by claim count, with an opioid prescribing rate of 3.9%. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Medical Physician Assistant is a mid-sized specialty nationwide, with 40,527 enrolled providers across 55 states and an average of 1,077 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

329 CONWAY ST
GREENFIELD, MA 01301

Provider Details

NPI 1821304312
Specialty Medical Physician Assistant
Credentials PA
Gender Male
NPI Issued 08/23/2010

Hospital and facility affiliations

Facilities where PETER BUCHANAN, PA 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.

VALLEY MEDICAL GROUP PC
GREENFIELD, 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 PETER BUCHANAN, PA. To verify PETER BUCHANAN, PA'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 · Typical

PETER BUCHANAN, PA — brand share 11.0%
Specialty average (est.)

11% brand-name claims vs 89% generic, on 3,282 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.

3,282
Total Claims
$346K
Total Drug Cost
400
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
7,008
Total Day Supply
200,332
Brand vs Generic
11% brand / 89% generic
Brand Drug Cost
$248K
Generic Drug Cost
$96K
Opioid Claims
128 (3.9% rate)
Antibiotic Claims
57

Patient Demographics

Average Patient Age
69.2 years
Avg HCC Risk Score
1.39
Gender Split
44% female / 56% male
Age Distribution
<65: 88, 65-74: 195, 75-84: 92, 85+: 25

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What PETER BUCHANAN, PA prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Atorvastatin Calcium
227
Lisinopril
183
Amlodipine Besylate
118
Omeprazole
90
Levothyroxine Sodium
88
Sertraline Hcl
86
Hydrochlorothiazide
85
Losartan Potassium
74
Gabapentin
66
Simvastatin
60

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Medical Physician Assistant Overview

How PETER BUCHANAN, PA fits within the Medical Physician Assistant landscape nationally.

40,527
Medical Physician Assistant Providers in US
55
States with Medical Physician Assistant
1,077
Avg Claims per Provider

PETER BUCHANAN, PA's 3,282 claims are above the specialty average of 1,077.

Nearby Medical Physician Assistant Providers in Massachusetts

Other clinicians with the same primary specialty enrolled in Massachusetts, drawn from the same CMS NPPES roster as BUCHANAN.

Compare Medical Physician Assistant nationally: see state-by-state distribution →

Frequently Asked Questions

What is PETER BUCHANAN, PA's specialty?
PETER BUCHANAN, PA specializes in Medical Physician Assistant and practices in GREENFIELD, Massachusetts. Credentials: PA.
How much does PETER BUCHANAN, PA prescribe under Medicare Part D?
In 2023, PETER BUCHANAN, PA wrote 3,282 Medicare Part D claims totaling $346K in drug costs for 400 beneficiaries.
Where is PETER BUCHANAN, PA located?
PETER BUCHANAN, PA is located at 329 CONWAY ST, GREENFIELD, MA, 01301. Phone: (413) 774-6301.
What is PETER BUCHANAN, PA's NPI number?
PETER BUCHANAN, PA's National Provider Identifier (NPI) is 1821304312, issued on 08/23/2010.
Does PETER BUCHANAN, PA prescribe more brand-name or generic drugs?
PETER BUCHANAN, PA's prescribing is 11% brand-name and 89% generic drugs by claim count, with $248K in brand drug costs.
Does PETER BUCHANAN, PA prescribe opioids?
Yes, PETER BUCHANAN, PA had 128 opioid claims in 2023 with an opioid prescribing rate of 3.9%.
How many Medical Physician Assistant providers are there in the US?
There are 40,527 Medical Physician Assistant providers across 55 states in the US. The average Medical Physician Assistant provider writes 1,077 Medicare Part D claims per year.
What drugs does PETER BUCHANAN, PA prescribe most often?
Based on 2023 Medicare Part D data, PETER BUCHANAN, PA's most frequently prescribed drugs include Atorvastatin Calcium, Lisinopril, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does PETER BUCHANAN, PA accept Medicare?
PETER BUCHANAN, PA appears in CMS Medicare data with 3,282 Part D claims and 400 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify PETER BUCHANAN, PA's credentials?
PETER BUCHANAN, PA's NPI is 1821304312 with credentials PA. 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

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