2026 NPPES data Internal Medicine Physician NPI 1063422749 MD
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Heather Wark, MD

Internal Medicine Physician in Northampton, 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 172,858 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
6K
Medicare Part D claims · 183 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
85%
generic claims · 15% brand-name · higher generic rates reduce patient out-of-pocket costs
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Heather Wark, MD filed 5,579 Medicare Part D claims in 2023 as a Internal Medicine Physician in Northampton, Massachusetts, prescribing 85% generic.

6K
Part D claims, 2023
85%
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.

Heather Wark, MD's Medicare Part D volume vs every U.S. prescriber

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

5,579 Top 5% higher than 95% 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

Board-eligible specialty (heuristic — not verified)

Heather Wark, MD 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 Heather Wark, MD?

Quality data not reported

NPI registry status

Active

Issued 08/08/2006

NPI 1063422749

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

5,579 105% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Massachusetts

How Internal Medicine Physician compares to other specialties among Massachusetts providers

Massachusetts providers

Largest specialties in Massachusetts (% of in-state providers)

Mental Health Counselor — 8.3%Mental Health Counselor8.3%Clinical Social Worker — 7.8%Clinical Social Worker7.8%Student in an Organized Health Care Education/Training Program — 6.2%Student in an Organized Health Care Education/Training Program6.2%Behavior Technician — 4.9%Behavior Technician4.9%Counselor — 4.3%Counselor4.3%Internal Medicine Physician — 3.7%Internal Medicine Physician3.7%
Largest specialties in Massachusetts (% of in-state providers)

Specialty board-certification context

Estimated specialty board-certified rate — Internal Medicine Physician (ABMS / AOA reference)

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

Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Internal Medicine Physician) — 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).

Heather Wark, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 548 ELM ST, Northampton, MA, 01060, with a listed phone of (413) 586-3150. NPI 1063422749 was issued on 08/08/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Wark 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 5,579 prescription claims written by this provider, covering 183 Medicare beneficiaries and totaling roughly $491K in drug spend, split 15% brand-name and 85% generic by claim count, with an opioid prescribing rate of 1.1%. 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.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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

548 ELM ST
Northampton, MA 01060

Provider Details

NPI 1063422749
Specialty Internal Medicine Physician
Credentials MD
Gender Female
NPI Issued 08/08/2006

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 Heather Wark, MD. To verify Heather Wark, 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.

Brand vs generic prescribing mix · Typical

Heather Wark, MD — brand share 15.0%
Internal Medicine Physician average

15% brand-name claims vs 85% generic, on 5,579 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.

5,579
Total Claims
$491K
Total Drug Cost
183
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
5,589
Total Day Supply
130,577
Brand vs Generic
15% brand / 85% generic
Brand Drug Cost
$326K
Generic Drug Cost
$163K
Opioid Claims
59 (1.1% rate)
Antibiotic Claims
145

Patient Demographics

Average Patient Age
76.8 years
Avg HCC Risk Score
2.53
Gender Split
55% female / 45% male
Age Distribution
<65: 24, 65-74: 61, 75-84: 45, 85+: 53

Top Prescribed Drugs (Medicare Part D)

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

What Heather Wark, MD 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
Eliquis
Apixaban
232
Clozapine
209
Atorvastatin Calcium
193
Levothyroxine Sodium
184
Gabapentin
174
Trazodone Hcl
163
Olanzapine
162
Amlodipine Besylate
139
Mirtazapine
134
Sertraline Hcl
134

* 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 Heather Wark, MD fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

Heather Wark, MD's 5,579 claims are above the specialty average of 2,716.

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 Wark.

Compare Internal Medicine 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 Internal Medicine 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.

Frequently Asked Questions

What is Heather Wark, MD's specialty?
Heather Wark, MD specializes in Internal Medicine Physician and practices in Northampton, Massachusetts. Credentials: MD.
How much does Heather Wark, MD prescribe under Medicare Part D?
In 2023, Heather Wark, MD wrote 5,579 Medicare Part D claims totaling $491K in drug costs for 183 beneficiaries.
Where is Heather Wark, MD located?
Heather Wark, MD is located at 548 ELM ST, Northampton, MA, 01060. Phone: (413) 586-3150.
What is Heather Wark, MD's NPI number?
Heather Wark, MD's National Provider Identifier (NPI) is 1063422749, issued on 08/08/2006.
Does Heather Wark, MD prescribe more brand-name or generic drugs?
Heather Wark, MD's prescribing is 15% brand-name and 85% generic drugs by claim count, with $326K in brand drug costs.
Does Heather Wark, MD prescribe opioids?
Yes, Heather Wark, MD had 59 opioid claims in 2023 with an opioid prescribing rate of 1.1%.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does Heather Wark, MD prescribe most often?
Based on 2023 Medicare Part D data, Heather Wark, MD's most frequently prescribed drugs include Eliquis, Clozapine, Atorvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Heather Wark, MD accept Medicare?
Heather Wark, MD appears in CMS Medicare data with 5,579 Part D claims and 183 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Heather Wark, MD's credentials?
Heather Wark, MD's NPI is 1063422749 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

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.