2026 NPPES data Internal Medicine Physician NPI 1942576947 M.D.
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WEI AN, M.D.

Internal Medicine Physician in WEST HARTFORD, Connecticut. 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
1K
Medicare Part D claims · 237 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
59%
generic claims · 41% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
79.5415/100
▼ 4 pts below national avg 83.1 · [object Object]
Industry payments
$1.2K
66 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: WEI AN, M.D. is a Internal Medicine Physician ([object Object]) practicing in WEST HARTFORD, Connecticut with a Medicare Part D prescribing footprint of 1K claims across 237 beneficiaries — 41% brand-name prescribing . Their CMS MIPS Final Score of 79.5415/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities . Industry payments of $1.2K across 66 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: WEI AN, M.D. reported a CMS MIPS final score of 79.5415 out of 100, below the 83.1 national average, and filed 1,235 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

WEI AN, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

WEI AN, M.D. at a glance

Near national average

NPI registry status

Active

Issued 03/24/2012

NPI 1942576947

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

1,235 55% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

MIPS final score

79.5415/100 3.558499999999995% pts

Above neutral band

vs 83.1 national avg

Specialty distribution in Connecticut

How Internal Medicine Physician compares to other specialties among Connecticut providers

Connecticut providers

Internal Medicine Physician share within Connecticut

1. Internal Medicine Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Internal Medicine Physician share within Connecticut

Medicare quality performance — MIPS

WEI AN, M.D.'s 2023 MIPS final score plotted against the Internal Medicine Physician national average

Near national average
MIPS Final Score
79.5415/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Internal Medicine Physician) — 79.5415/100 vs national avg 83.1

0%100%National avg83%79.5%
MIPS final score (Internal Medicine Physician) — 79.5415/100 vs national avg 83.1

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).

WEI AN, M.D. is a Internal Medicine Physician provider practicing in WEST HARTFORD, Connecticut, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1942576947. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

WEI AN, M.D. appears in the CMS NPPES registry as a Internal Medicine Physician provider holding M.D. credentials at 836 FARMINGTON AVE STE 207, WEST HARTFORD, CT, 06119, with a listed phone of (860) 232-9911. NPI 1942576947 was issued on 03/24/2012. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what AN 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 1,235 prescription claims written by this provider, covering 237 Medicare beneficiaries and totaling roughly $634K in drug spend, split 41% brand-name and 59% generic by claim count. 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 79.5415/100 for the 2023 performance year (Quality 95.3728, Cost 36.432), compared with the national average of 83.1.

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

836 FARMINGTON AVE STE 207
WEST HARTFORD, CT 06119

Provider Details

NPI 1942576947
Specialty Internal Medicine Physician
Credentials M.D.
Gender Male
NPI Issued 03/24/2012

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

79.5415
Final Score
Avg: 83.1
95.3728
Quality
36.432
Cost
100
Promoting Interoperability

Reporting: Group practice

Hospital and facility affiliations

Facilities where WEI AN, M.D. 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.

CONNECTICUT ASTHMA AND ALLERGY CENTER LLC
WEST HARTFORD, CT

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Industry payments received (2024) — CMS Open Payments transparency data

The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for WEI AN, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$1.2K

Largest payer

GlaxoSmithKline, LLC.

Most common payment type

Food and Beverage

Industry payments are not necessarily indicators of bias — they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.

Brand vs generic prescribing mix · Above average

WEI AN, M.D. — brand share 41.0%
Specialty average (est.)

41% brand-name claims vs 59% generic, on 1,235 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.

1,235
Total Claims
$634K
Total Drug Cost
237
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,939
Total Day Supply
54,523
Brand vs Generic
41% brand / 59% generic
Brand Drug Cost
$556K
Generic Drug Cost
$78K
Antibiotic Claims
25

Patient Demographics

Average Patient Age
69.6 years
Avg HCC Risk Score
0.93
Gender Split
76% female / 24% male

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Albuterol Sulfate Hfa
Albuterol Sulfate
169
Trelegy Ellipta
Fluticasone/Umeclidin/Vilanter
127
Montelukast Sodium
98
Azelastine-Fluticasone
Azelastine/Fluticasone
90
Wixela Inhub
Fluticasone Propion/Salmeterol
60
Azelastine Hcl
58
Ipratropium Bromide
58
Prednisone
51
Spiriva Respimat
Tiotropium Bromide
41
Fluticasone Propionate
39

* 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 WEI AN, M.D. 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

WEI AN, M.D.'s 1,235 claims are below the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Connecticut

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

Compare Internal Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is WEI AN, M.D.'s specialty?
WEI AN, M.D. specializes in Internal Medicine Physician and practices in WEST HARTFORD, Connecticut. Credentials: M.D..
How much does WEI AN, M.D. prescribe under Medicare Part D?
In 2023, WEI AN, M.D. wrote 1,235 Medicare Part D claims totaling $634K in drug costs for 237 beneficiaries.
What is WEI AN, M.D.'s Medicare quality score?
WEI AN, M.D. has a CMS MIPS Final Score of 79.5415/100 (Quality: 95.3728, Cost: 36.432). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is WEI AN, M.D. located?
WEI AN, M.D. is located at 836 FARMINGTON AVE STE 207, WEST HARTFORD, CT, 06119. Phone: (860) 232-9911.
What is WEI AN, M.D.'s NPI number?
WEI AN, M.D.'s National Provider Identifier (NPI) is 1942576947, issued on 03/24/2012.
Does WEI AN, M.D. prescribe more brand-name or generic drugs?
WEI AN, M.D.'s prescribing is 41% brand-name and 59% generic drugs by claim count, with $556K in brand drug costs.
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 WEI AN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, WEI AN, M.D.'s most frequently prescribed drugs include Albuterol Sulfate Hfa, Trelegy Ellipta, Montelukast Sodium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does WEI AN, M.D. accept Medicare?
WEI AN, M.D. appears in CMS Medicare data with 1,235 Part D claims and 237 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify WEI AN, M.D.'s credentials?
WEI AN, M.D.'s NPI is 1942576947 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

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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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