2026 NPPES data Allergy & Immunology (Internal Medicine) Physician NPI 1841225430 M.D.
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MICHAEL VOLZ, M.D.

Allergy & Immunology (Internal Medicine) Physician in AUSTIN, Texas. 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
937
Medicare Part D claims · 133 beneficiaries · Allergy & Immunology (Internal Medicine) Physician avg: 798
Industry payments
$2.9K
6 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: MICHAEL VOLZ, M.D. is a Allergy & Immunology (Internal Medicine) Physician ([object Object]) practicing in AUSTIN, Texas with a Medicare Part D prescribing footprint of 937 claims across 133 beneficiaries . Industry payments of $2.9K across 6 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: MICHAEL VOLZ, M.D. filed 937 Medicare Part D claims in 2023 across AUSTIN, Texas. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

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

MICHAEL VOLZ, M.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 07/11/2006

NPI 1841225430

Primary specialty

Allergy & Immunology (Internal Medicine) Physician

Niche

520 US NPIs in this specialty

Medicare Part D claims

937 17% vs specialty avg

2023 prescription claims

Specialty avg: 798

Specialty distribution in Texas

How Allergy & Immunology (Internal Medicine) Physician compares to other specialties among Texas providers

Texas providers

Allergy & Immunology (Internal Medicine) Physician share within Texas

1. Allergy & Immunology (Internal Medicine) Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Allergy & Immunology (Internal Medicine) Physician share within Texas

Specialty board-certification context

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

Quality data not reported
Est. board-certified rate
78%
Allergy & Immunology (Internal Medicine) Physician ABMS/AOA estimate

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

0%100%78%
Est. board-certified rate (Allergy & Immunology (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).

MICHAEL VOLZ, M.D. is a Allergy & Immunology (Internal Medicine) Physician provider practicing in AUSTIN, Texas, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1841225430. 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.

MICHAEL VOLZ, M.D. appears in the CMS NPPES registry as a Allergy & Immunology (Internal Medicine) Physician provider holding M.D. credentials at 9835 N LAKE CREEK PKWY, AUSTIN, TX, 78717, with a listed phone of (832) 824-1000. NPI 1841225430 was issued on 07/11/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what VOLZ 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 937 prescription claims written by this provider, covering 133 Medicare beneficiaries and totaling roughly $228K in drug spend. 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.

Allergy & Immunology (Internal Medicine) Physician is a narrow specialty nationwide, with 520 enrolled providers across 48 states and an average of 798 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

9835 N LAKE CREEK PKWY
AUSTIN, TX 78717

Provider Details

NPI 1841225430
Specialty Allergy & Immunology (Internal Medicine) Physician
Credentials M.D.
Gender Male
NPI Issued 07/11/2006

Hospital and facility affiliations

Facilities where MICHAEL VOLZ, 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.

TEXAS CHILDRENS PHYSICIAN GROUP
AUSTIN, TX

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 MICHAEL VOLZ, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$2.9K

Largest payer

PFIZER INC.

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.

License & disciplinary context — Texas TMB 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 ~77K Texas medical licensees in 2023 — they are NOT specific to MICHAEL VOLZ, M.D.. To verify MICHAEL VOLZ, M.D.'s current license status, search the TMB public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

344
Total board actions, Texas 2023
Across 334 cases
4.47
Actions per 1,000 licensees
Texas statewide rate
probation
Most common action type
94 cases

TMB 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 Texas disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Medicare Part D Prescribing Data

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

937
Total Claims
$228K
Total Drug Cost
133
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,424
Total Day Supply
38,407
Generic Drug Cost
$43K
Antibiotic Claims
119

Patient Demographics

Average Patient Age
70.9 years
Avg HCC Risk Score
1.52
Gender Split
71% female / 29% 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
Montelukast Sodium
148
Breo Ellipta
Fluticasone/Vilanterol
58
Prednisone
53
Ceftriaxone
Ceftriaxone Sodium
52
Trelegy Ellipta
Fluticasone/Umeclidin/Vilanter
41
Cromolyn Sodium
32
Arnuity Ellipta
Fluticasone Furoate
28
Albuterol Sulfate Hfa
Albuterol Sulfate
24
Hydroxychloroquine Sulfate
22
Fluticasone-Salmeterol
Fluticasone Propion/Salmeterol
21

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

Allergy & Immunology (Internal Medicine) Physician Overview

How MICHAEL VOLZ, M.D. fits within the Allergy & Immunology (Internal Medicine) Physician landscape nationally.

520
Allergy & Immunology (Internal Medicine) Physician Providers in US
48
States with Allergy & Immunology (Internal Medicine) Physician
798
Avg Claims per Provider

MICHAEL VOLZ, M.D.'s 937 claims are above the specialty average of 798.

Nearby Allergy & Immunology (Internal Medicine) Physician Providers in Texas

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

Compare Allergy & Immunology (Internal Medicine) Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is MICHAEL VOLZ, M.D.'s specialty?
MICHAEL VOLZ, M.D. specializes in Allergy & Immunology (Internal Medicine) Physician and practices in AUSTIN, Texas. Credentials: M.D..
How much does MICHAEL VOLZ, M.D. prescribe under Medicare Part D?
In 2023, MICHAEL VOLZ, M.D. wrote 937 Medicare Part D claims totaling $228K in drug costs for 133 beneficiaries.
Where is MICHAEL VOLZ, M.D. located?
MICHAEL VOLZ, M.D. is located at 9835 N LAKE CREEK PKWY, AUSTIN, TX, 78717. Phone: (832) 824-1000.
What is MICHAEL VOLZ, M.D.'s NPI number?
MICHAEL VOLZ, M.D.'s National Provider Identifier (NPI) is 1841225430, issued on 07/11/2006.
How many Allergy & Immunology (Internal Medicine) Physician providers are there in the US?
There are 520 Allergy & Immunology (Internal Medicine) Physician providers across 48 states in the US. The average Allergy & Immunology (Internal Medicine) Physician provider writes 798 Medicare Part D claims per year.
What drugs does MICHAEL VOLZ, M.D. prescribe most often?
Based on 2023 Medicare Part D data, MICHAEL VOLZ, M.D.'s most frequently prescribed drugs include Montelukast Sodium, Breo Ellipta, Prednisone. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does MICHAEL VOLZ, M.D. accept Medicare?
MICHAEL VOLZ, M.D. appears in CMS Medicare data with 937 Part D claims and 133 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MICHAEL VOLZ, M.D.'s credentials?
MICHAEL VOLZ, M.D.'s NPI is 1841225430 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.
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