2026 NPPES data Internal Medicine Physician NPI 1326011271 MD
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NEAL HOLZUM, MD

Internal Medicine 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
757
Medicare Part D claims · 304 beneficiaries · Internal Medicine Physician avg: 3K

What the federal data shows

NEAL HOLZUM, MD filed 757 Medicare Part D claims in 2023 as a Internal Medicine Physician in O FALLON, Missouri.

757
Part D claims, 2023

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.

NEAL HOLZUM, MD's Medicare Part D volume vs every U.S. prescriber

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

757 Top 29% higher than 71% 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%). This entry sits in this band. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. 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)

NEAL HOLZUM, 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 NEAL HOLZUM, MD?

Quality data not reported

NPI registry status

Active

Issued 02/10/2006

NPI 1326011271

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

757 72% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Missouri

How Internal Medicine Physician compares to other specialties among Missouri providers

Missouri providers

Internal Medicine Physician share within Missouri

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

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).

NEAL HOLZUM, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 2 PROGRESS POINT CT, O FALLON, MO, 63368, with a listed phone of (636) 236-9945. NPI 1326011271 was issued on 02/10/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what HOLZUM 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 757 prescription claims written by this provider, covering 304 Medicare beneficiaries and totaling roughly $44K in drug spend, with an opioid prescribing rate of 9.6%. 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

2 PROGRESS POINT CT
O FALLON, MO 63368

Provider Details

NPI 1326011271
Specialty Internal Medicine Physician
Credentials MD
Gender Male
NPI Issued 02/10/2006

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

757
Total Claims
$44K
Total Drug Cost
304
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
797
Total Day Supply
16,830
Generic Drug Cost
$7K
Opioid Claims
73 (9.6% rate)
Antibiotic Claims
147

Patient Demographics

Average Patient Age
74.5 years
Avg HCC Risk Score
1.71
Gender Split
60% female / 40% male
Age Distribution
<65: 42, 65-74: 107, 75-84: 103, 85+: 52

Top Prescribed Drugs (Medicare Part D)

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

What NEAL HOLZUM, 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
Amoxicillin-Clavulanate Potass
Amoxicillin/Potassium Clav
53
Metoprolol Tartrate
42
Lisinopril
37
Hydrocodone-Acetaminophen
Hydrocodone/Acetaminophen
29
Prednisone
28
Levothyroxine Sodium
25
Furosemide
24
Levofloxacin
23
Oxycodone Hcl
23
Anoro Ellipta
Umeclidinium Brm/Vilanterol Tr
22

* 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 NEAL HOLZUM, 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

NEAL HOLZUM, MD's 757 claims are below the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Missouri

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

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

Frequently Asked Questions

What is NEAL HOLZUM, MD's specialty?
NEAL HOLZUM, MD specializes in Internal Medicine Physician and practices in O FALLON, Missouri. Credentials: MD.
How much does NEAL HOLZUM, MD prescribe under Medicare Part D?
In 2023, NEAL HOLZUM, MD wrote 757 Medicare Part D claims totaling $44K in drug costs for 304 beneficiaries.
Where is NEAL HOLZUM, MD located?
NEAL HOLZUM, MD is located at 2 PROGRESS POINT CT, O FALLON, MO, 63368. Phone: (636) 236-9945.
What is NEAL HOLZUM, MD's NPI number?
NEAL HOLZUM, MD's National Provider Identifier (NPI) is 1326011271, issued on 02/10/2006.
Does NEAL HOLZUM, MD prescribe opioids?
Yes, NEAL HOLZUM, MD had 73 opioid claims in 2023 with an opioid prescribing rate of 9.6%.
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 NEAL HOLZUM, MD prescribe most often?
Based on 2023 Medicare Part D data, NEAL HOLZUM, MD's most frequently prescribed drugs include Amoxicillin-Clavulanate Potass, Metoprolol Tartrate, Lisinopril. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does NEAL HOLZUM, MD accept Medicare?
NEAL HOLZUM, MD appears in CMS Medicare data with 757 Part D claims and 304 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify NEAL HOLZUM, MD's credentials?
NEAL HOLZUM, MD's NPI is 1326011271 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