2026 NPPES data Medical Toxicology (Emergency Medicine) Physician NPI 1235591439
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GRANT COMSTOCK

Medical Toxicology (Emergency Medicine) Physician in MILWAUKEE, Wisconsin. 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
183
Medicare Part D claims · 140 beneficiaries · Medical Toxicology (Emergency Medicine) Physician avg: 329
Generic prescribing
93%
generic claims · 7% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

GRANT COMSTOCK filed 183 Medicare Part D claims in 2023 as a Medical Toxicology (Emergency Medicine) Physician in MILWAUKEE, Wisconsin, prescribing 93% generic.

183
Part D claims, 2023
93%
generic prescribing
Likely
board-certified (heuristic)

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.

GRANT COMSTOCK's Medicare Part D volume vs every U.S. prescriber

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

183 35th percentile higher than 35% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). This entry sits in this band. 200–400: 182,923 prescribers (13%). Above this entry. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 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 certification likely (heuristic — not verified)

GRANT COMSTOCK 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).

What does the federal data show about GRANT COMSTOCK?

Quality data not reported

NPI registry status

Active

Issued 03/25/2016

NPI 1235591439

Primary specialty

Medical Toxicology (Emergency Medicine) Physician

Rare

226 US NPIs in this specialty

Medicare Part D claims

183 44% vs specialty avg

2023 prescription claims

Specialty avg: 329

Specialty distribution in Wisconsin

How Medical Toxicology (Emergency Medicine) Physician compares to other specialties among Wisconsin providers

Wisconsin providers

Medical Toxicology (Emergency Medicine) Physician share within Wisconsin

1. Medical Toxicology (Emergency Medicine) Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Medical Toxicology (Emergency Medicine) Physician share within Wisconsin

Specialty board-certification context

Estimated specialty board-certified rate — Medical Toxicology (Emergency Medicine) Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Medical Toxicology (Emergency Medicine) Physician ABMS/AOA estimate

Est. board-certified rate (Medical Toxicology (Emergency Medicine) Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Medical Toxicology (Emergency 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).

GRANT COMSTOCK appears in the CMS NPPES registry as a Medical Toxicology (Emergency Medicine) Physician provider at 9200 W WISCONSIN AVE, MILWAUKEE, WI, 53226, with a listed phone of (414) 955-6450. NPI 1235591439 was issued on 03/25/2016. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what COMSTOCK 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 183 prescription claims written by this provider, covering 140 Medicare beneficiaries and totaling roughly $10K in drug spend, split 7% brand-name and 93% generic by claim count, with an opioid prescribing rate of 6.6%. 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.

Medical Toxicology (Emergency Medicine) Physician is a narrow specialty nationwide, with 226 enrolled providers across 39 states and an average of 329 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

9200 W WISCONSIN AVE
MILWAUKEE, WI 53226

Provider Details

NPI 1235591439
Specialty Medical Toxicology (Emergency Medicine) Physician
Gender Male
NPI Issued 03/25/2016

Hospital and facility affiliations

Facilities where GRANT COMSTOCK 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.

THE MEDICAL COLLEGE OF WISCONSIN INC
MILWAUKEE, WI

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

Brand vs generic prescribing mix · Generic-heavy

GRANT COMSTOCK — brand share 7.0%
Specialty average (est.)

7% brand-name claims vs 93% generic, on 183 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.

183
Total Claims
$10K
Total Drug Cost
140
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
187
Total Day Supply
1,912
Brand vs Generic
7% brand / 93% generic
Brand Drug Cost
$8K
Generic Drug Cost
$2K
Opioid Claims
12 (6.6% rate)
Antibiotic Claims
71

Patient Demographics

Average Patient Age
71.3 years
Avg HCC Risk Score
2.26
Gender Split
56% female / 44% male
Age Distribution
<65: 23, 65-74: 57, 75-84: 48, 85+: 12

Top Prescribed Drugs (Medicare Part D)

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

What GRANT COMSTOCK 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
Cefdinir
19
Cephalexin
16
Prednisone
14
Ondansetron Odt
Ondansetron
13
Oxycodone Hcl
12
Doxycycline Hyclate
11

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

Medical Toxicology (Emergency Medicine) Physician Overview

How GRANT COMSTOCK fits within the Medical Toxicology (Emergency Medicine) Physician landscape nationally.

226
Medical Toxicology (Emergency Medicine) Physician Providers in US
39
States with Medical Toxicology (Emergency Medicine) Physician
329
Avg Claims per Provider

GRANT COMSTOCK's 183 claims are below the specialty average of 329.

Nearby Medical Toxicology (Emergency Medicine) Physician Providers in Wisconsin

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

Compare Medical Toxicology (Emergency Medicine) Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is GRANT COMSTOCK's specialty?
GRANT COMSTOCK specializes in Medical Toxicology (Emergency Medicine) Physician and practices in MILWAUKEE, Wisconsin.
How much does GRANT COMSTOCK prescribe under Medicare Part D?
In 2023, GRANT COMSTOCK wrote 183 Medicare Part D claims totaling $10K in drug costs for 140 beneficiaries.
Where is GRANT COMSTOCK located?
GRANT COMSTOCK is located at 9200 W WISCONSIN AVE, MILWAUKEE, WI, 53226. Phone: (414) 955-6450.
What is GRANT COMSTOCK's NPI number?
GRANT COMSTOCK's National Provider Identifier (NPI) is 1235591439, issued on 03/25/2016.
Does GRANT COMSTOCK prescribe more brand-name or generic drugs?
GRANT COMSTOCK's prescribing is 7% brand-name and 93% generic drugs by claim count, with $8K in brand drug costs.
Does GRANT COMSTOCK prescribe opioids?
Yes, GRANT COMSTOCK had 12 opioid claims in 2023 with an opioid prescribing rate of 6.6%.
How many Medical Toxicology (Emergency Medicine) Physician providers are there in the US?
There are 226 Medical Toxicology (Emergency Medicine) Physician providers across 39 states in the US. The average Medical Toxicology (Emergency Medicine) Physician provider writes 329 Medicare Part D claims per year.
What drugs does GRANT COMSTOCK prescribe most often?
Based on 2023 Medicare Part D data, GRANT COMSTOCK's most frequently prescribed drugs include Cefdinir, Cephalexin, Prednisone. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does GRANT COMSTOCK accept Medicare?
GRANT COMSTOCK appears in CMS Medicare data with 183 Part D claims and 140 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify GRANT COMSTOCK's credentials?
GRANT COMSTOCK's NPI is 1235591439. 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