2026 NPPES data Rheumatology Physician NPI 1568535664 MD
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LESLEY FEIN, MD

Rheumatology Physician in WEST CALDWELL, New Jersey. 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
2K
Medicare Part D claims · 65 beneficiaries · Rheumatology Physician avg: 2K
Generic prescribing
94%
generic claims · 6% brand-name · higher generic rates reduce patient out-of-pocket costs
What the federal data reveals: LESLEY FEIN, MD is a Rheumatology Physician ([object Object]) practicing in WEST CALDWELL, New Jersey with a Medicare Part D prescribing footprint of 2K claims across 65 beneficiaries — 6% brand-name prescribing .

What stands out: LESLEY FEIN, MD filed 1,668 Medicare Part D claims in 2023 across WEST CALDWELL, New Jersey. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

LESLEY FEIN, 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).

LESLEY FEIN, MD at a glance

Quality data not reported

NPI registry status

Active

Issued 11/16/2006

NPI 1568535664

Primary specialty

Rheumatology Physician

Mid-sized

6,181 US NPIs in this specialty

Medicare Part D claims

1,668 19% vs specialty avg

2023 prescription claims

Specialty avg: 2,054

Specialty distribution in New Jersey

How Rheumatology Physician compares to other specialties among New Jersey providers

New Jersey providers

Rheumatology Physician share within New Jersey

1. Rheumatology Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Rheumatology Physician share within New Jersey

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (Rheumatology 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).

LESLEY FEIN, MD is a Rheumatology Physician provider practicing in WEST CALDWELL, New Jersey, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1568535664. 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.

LESLEY FEIN, MD appears in the CMS NPPES registry as a Rheumatology Physician provider holding MD credentials at 1099 BLOOMFIELD AVE, WEST CALDWELL, NJ, 07006, with a listed phone of (973) 575-0338. NPI 1568535664 was issued on 11/16/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what FEIN 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 1,668 prescription claims written by this provider, covering 65 Medicare beneficiaries and totaling roughly $378K in drug spend, split 6% brand-name and 94% generic by claim count, with an opioid prescribing rate of 9.1%. 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.

Rheumatology Physician is a mid-sized specialty nationwide, with 6,181 enrolled providers across 52 states and an average of 2,054 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

1099 BLOOMFIELD AVE
WEST CALDWELL, NJ 07006

Provider Details

NPI 1568535664
Specialty Rheumatology Physician
Credentials MD
Gender Female
NPI Issued 11/16/2006

Brand vs generic prescribing mix · Generic-heavy

LESLEY FEIN, MD — brand share 6.0%
Specialty average (est.)

6% brand-name claims vs 94% generic, on 1,668 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.

1,668
Total Claims
$378K
Total Drug Cost
65
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
2,045
Total Day Supply
52,570
Brand vs Generic
6% brand / 94% generic
Brand Drug Cost
$217K
Generic Drug Cost
$160K
Opioid Claims
151 (9.1% rate)
Antibiotic Claims
522

Patient Demographics

Average Patient Age
66.8 years
Avg HCC Risk Score
0.95
Gender Split
68% female / 32% male
Age Distribution
<65: 22, 65-74: 28, 75-84: N/A, 85+: N/A

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Tinidazole
133
Minocycline Hcl
125
Doxycycline Hyclate
107
Oxycodone Hcl
77
Hydroxychloroquine Sulfate
76
Atovaquone-Proguanil Hcl
Atovaquone/Proguanil Hcl
69
Rifampin
68
Valganciclovir Hcl
52
Valacyclovir
Valacyclovir Hcl
50
Clonazepam
44

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

Rheumatology Physician Overview

How LESLEY FEIN, MD fits within the Rheumatology Physician landscape nationally.

6,181
Rheumatology Physician Providers in US
52
States with Rheumatology Physician
2,054
Avg Claims per Provider

LESLEY FEIN, MD's 1,668 claims are below the specialty average of 2,054.

Nearby Rheumatology Physician Providers in New Jersey

Other clinicians with the same primary specialty enrolled in New Jersey, drawn from the same CMS NPPES roster as FEIN.

Compare Rheumatology Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is LESLEY FEIN, MD's specialty?
LESLEY FEIN, MD specializes in Rheumatology Physician and practices in WEST CALDWELL, New Jersey. Credentials: MD.
How much does LESLEY FEIN, MD prescribe under Medicare Part D?
In 2023, LESLEY FEIN, MD wrote 1,668 Medicare Part D claims totaling $378K in drug costs for 65 beneficiaries.
Where is LESLEY FEIN, MD located?
LESLEY FEIN, MD is located at 1099 BLOOMFIELD AVE, WEST CALDWELL, NJ, 07006. Phone: (973) 575-0338.
What is LESLEY FEIN, MD's NPI number?
LESLEY FEIN, MD's National Provider Identifier (NPI) is 1568535664, issued on 11/16/2006.
Does LESLEY FEIN, MD prescribe more brand-name or generic drugs?
LESLEY FEIN, MD's prescribing is 6% brand-name and 94% generic drugs by claim count, with $217K in brand drug costs.
Does LESLEY FEIN, MD prescribe opioids?
Yes, LESLEY FEIN, MD had 151 opioid claims in 2023 with an opioid prescribing rate of 9.1%.
How many Rheumatology Physician providers are there in the US?
There are 6,181 Rheumatology Physician providers across 52 states in the US. The average Rheumatology Physician provider writes 2,054 Medicare Part D claims per year.
What drugs does LESLEY FEIN, MD prescribe most often?
Based on 2023 Medicare Part D data, LESLEY FEIN, MD's most frequently prescribed drugs include Tinidazole, Minocycline Hcl, Doxycycline Hyclate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does LESLEY FEIN, MD accept Medicare?
LESLEY FEIN, MD appears in CMS Medicare data with 1,668 Part D claims and 65 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify LESLEY FEIN, MD's credentials?
LESLEY FEIN, MD's NPI is 1568535664 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