2026 NPPES data General Practice Physician NPI 1861481558 DO
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JOHN ANZALONE, DO

General Practice Physician in O FALLON, Missouri. 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
178
Medicare Part D claims · 64 beneficiaries · General Practice Physician avg: 3K
Generic prescribing
79%
generic claims · 21% brand-name · higher generic rates reduce patient out-of-pocket costs
What the federal data reveals: JOHN ANZALONE, DO is a General Practice Physician ([object Object]) practicing in O FALLON, Missouri with a Medicare Part D prescribing footprint of 178 claims across 64 beneficiaries — 21% brand-name prescribing .

What stands out: JOHN ANZALONE, DO filed 178 Medicare Part D claims in 2023 across O FALLON, Missouri. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

JOHN ANZALONE, DO 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).

JOHN ANZALONE, DO at a glance

Quality data not reported

NPI registry status

Active

Issued 10/17/2005

NPI 1861481558

Primary specialty

General Practice Physician

Mid-sized

16,677 US NPIs in this specialty

Medicare Part D claims

178 94% vs specialty avg

2023 prescription claims

Specialty avg: 2,872

Specialty distribution in Missouri

How General Practice Physician compares to other specialties among Missouri providers

Missouri providers

General Practice Physician share within Missouri

1. General Practice Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
General Practice Physician share within Missouri

Specialty board-certification context

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

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

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

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

JOHN ANZALONE, DO is a General Practice Physician provider practicing in O FALLON, Missouri, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: DO. NPI: 1861481558. 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.

JOHN ANZALONE, DO appears in the CMS NPPES registry as a General Practice Physician provider holding DO credentials at 1055 E TERRA LN, O FALLON, MO, 63366, with a listed phone of (636) 272-6161. NPI 1861481558 was issued on 10/17/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ANZALONE 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 178 prescription claims written by this provider, covering 64 Medicare beneficiaries and totaling roughly $27K in drug spend, split 21% brand-name and 79% 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.

General Practice Physician is a mid-sized specialty nationwide, with 16,677 enrolled providers across 56 states and an average of 2,872 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

1055 E TERRA LN
O FALLON, MO 63366

Provider Details

NPI 1861481558
Specialty General Practice Physician
Credentials DO
Gender Male
NPI Issued 10/17/2005

Brand vs generic prescribing mix · Typical

JOHN ANZALONE, DO — brand share 21.0%
Specialty average (est.)

21% brand-name claims vs 79% generic, on 178 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.

178
Total Claims
$27K
Total Drug Cost
64
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
342
Total Day Supply
10,105
Brand vs Generic
21% brand / 79% generic
Brand Drug Cost
$24K
Generic Drug Cost
$3K

Patient Demographics

Average Patient Age
75.3 years
Avg HCC Risk Score
1.29
Gender Split
66% female / 34% 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
Amlodipine Besylate
30
Atorvastatin Calcium
12
Eliquis
Apixaban
11

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

General Practice Physician Overview

How JOHN ANZALONE, DO fits within the General Practice Physician landscape nationally.

16,677
General Practice Physician Providers in US
56
States with General Practice Physician
2,872
Avg Claims per Provider

JOHN ANZALONE, DO's 178 claims are below the specialty average of 2,872.

Nearby General Practice Physician Providers in Missouri

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

Compare General Practice Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is JOHN ANZALONE, DO's specialty?
JOHN ANZALONE, DO specializes in General Practice Physician and practices in O FALLON, Missouri. Credentials: DO.
How much does JOHN ANZALONE, DO prescribe under Medicare Part D?
In 2023, JOHN ANZALONE, DO wrote 178 Medicare Part D claims totaling $27K in drug costs for 64 beneficiaries.
Where is JOHN ANZALONE, DO located?
JOHN ANZALONE, DO is located at 1055 E TERRA LN, O FALLON, MO, 63366. Phone: (636) 272-6161.
What is JOHN ANZALONE, DO's NPI number?
JOHN ANZALONE, DO's National Provider Identifier (NPI) is 1861481558, issued on 10/17/2005.
Does JOHN ANZALONE, DO prescribe more brand-name or generic drugs?
JOHN ANZALONE, DO's prescribing is 21% brand-name and 79% generic drugs by claim count, with $24K in brand drug costs.
How many General Practice Physician providers are there in the US?
There are 16,677 General Practice Physician providers across 56 states in the US. The average General Practice Physician provider writes 2,872 Medicare Part D claims per year.
What drugs does JOHN ANZALONE, DO prescribe most often?
Based on 2023 Medicare Part D data, JOHN ANZALONE, DO's most frequently prescribed drugs include Amlodipine Besylate, Atorvastatin Calcium, Eliquis. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JOHN ANZALONE, DO accept Medicare?
JOHN ANZALONE, DO appears in CMS Medicare data with 178 Part D claims and 64 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JOHN ANZALONE, DO's credentials?
JOHN ANZALONE, DO's NPI is 1861481558 with credentials DO. 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