2026 NPPES data Critical Care Medicine (Internal Medicine) Physician NPI 1225158694 M.D.
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WARREN FIELDS, M.D.

Critical Care Medicine (Internal Medicine) Physician in ROYAL OAK, Michigan. 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 · 324 beneficiaries · Critical Care Medicine (Internal Medicine) Physician avg: 1K
Industry payments
$1.3K
68 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

WARREN FIELDS, M.D. filed 1,901 Medicare Part D claims in 2023 as a Critical Care Medicine (Internal Medicine) Physician in ROYAL OAK, Michigan.

2K
Part D claims, 2023
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.

WARREN FIELDS, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

1,901 Top 16% higher than 84% 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%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). This entry sits in this band. 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)

WARREN FIELDS, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 2 hospital affiliations — 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 WARREN FIELDS, M.D.?

Quality data not reported

NPI registry status

Active

Issued 03/30/2007

NPI 1225158694

Primary specialty

Critical Care Medicine (Internal Medicine) Physician

Mid-sized

6,631 US NPIs in this specialty

Medicare Part D claims

1,901 78% vs specialty avg

2023 prescription claims

Specialty avg: 1,069

Specialty distribution in Michigan

How Critical Care Medicine (Internal Medicine) Physician compares to other specialties among Michigan providers

Michigan providers

Critical Care Medicine (Internal Medicine) Physician share within Michigan

1. Critical Care Medicine (Internal Medicine) Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Critical Care Medicine (Internal Medicine) Physician share within Michigan

Specialty board-certification context

Estimated specialty board-certified rate — Critical Care Medicine (Internal Medicine) Physician (ABMS / AOA reference)

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

Est. board-certified rate (Critical Care Medicine (Internal Medicine) Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Critical Care Medicine (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).

WARREN FIELDS, M.D. appears in the CMS NPPES registry as a Critical Care Medicine (Internal Medicine) Physician provider holding M.D. credentials at 30701 WOODWARD AVE STE 200, ROYAL OAK, MI, 48073, with a listed phone of (248) 548-2114. NPI 1225158694 was issued on 03/30/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what FIELDS 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 1,901 prescription claims written by this provider, covering 324 Medicare beneficiaries and totaling roughly $813K 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.

Critical Care Medicine (Internal Medicine) Physician is a mid-sized specialty nationwide, with 6,631 enrolled providers across 53 states and an average of 1,069 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

30701 WOODWARD AVE STE 200
ROYAL OAK, MI 48073

Provider Details

NPI 1225158694
Specialty Critical Care Medicine (Internal Medicine) Physician
Credentials M.D.
Gender Male
NPI Issued 03/30/2007

Hospital and facility affiliations

Facilities where WARREN FIELDS, 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.

BEAUMONT MEDICAL GROUP- SPECIALTY SERVICES
FARMINGTON HILLS, MI
GREENBERGER WU DUNN AND FIELDS PLLC
ROYAL OAK, MI

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 WARREN FIELDS, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$1.3K

Largest payer

AstraZeneca Pharmaceuticals LP

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 — Michigan MI-BOM 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 ~41K Michigan medical licensees in 2023 — they are NOT specific to WARREN FIELDS, M.D.. To verify WARREN FIELDS, M.D.'s current license status, search the MI-BOM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

123
Total board actions, Michigan 2023
Across 120 cases
3.00
Actions per 1,000 licensees
Michigan statewide rate
probation
Most common action type
44 cases

MI-BOM 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 Michigan 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.

1,901
Total Claims
$813K
Total Drug Cost
324
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
2,619
Total Day Supply
68,407
Generic Drug Cost
$161K
Antibiotic Claims
158

Patient Demographics

Average Patient Age
75.4 years
Avg HCC Risk Score
1.95
Gender Split
62% female / 38% male
Age Distribution
<65: 23, 65-74: 118, 75-84: 136, 85+: 47

Top Prescribed Drugs (Medicare Part D)

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

What WARREN FIELDS, M.D. 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
Albuterol Sulfate Hfa
Albuterol Sulfate
305
Prednisone
250
Trelegy Ellipta
Fluticasone/Umeclidin/Vilanter
170
Breztri Aerosphere
Budesonide/Glycopyr/Formoterol
95
Stiolto Respimat
Tiotropium Br/Olodaterol Hcl
61
Azelastine Hcl
58
Azithromycin
58
Ventolin Hfa
Albuterol Sulfate
57
Montelukast Sodium
54
Spiriva Respimat
Tiotropium Bromide
52

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

Critical Care Medicine (Internal Medicine) Physician Overview

How WARREN FIELDS, M.D. fits within the Critical Care Medicine (Internal Medicine) Physician landscape nationally.

6,631
Critical Care Medicine (Internal Medicine) Physician Providers in US
53
States with Critical Care Medicine (Internal Medicine) Physician
1,069
Avg Claims per Provider

WARREN FIELDS, M.D.'s 1,901 claims are above the specialty average of 1,069.

Nearby Critical Care Medicine (Internal Medicine) Physician Providers in Michigan

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

Compare Critical Care Medicine (Internal Medicine) Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is WARREN FIELDS, M.D.'s specialty?
WARREN FIELDS, M.D. specializes in Critical Care Medicine (Internal Medicine) Physician and practices in ROYAL OAK, Michigan. Credentials: M.D..
How much does WARREN FIELDS, M.D. prescribe under Medicare Part D?
In 2023, WARREN FIELDS, M.D. wrote 1,901 Medicare Part D claims totaling $813K in drug costs for 324 beneficiaries.
Where is WARREN FIELDS, M.D. located?
WARREN FIELDS, M.D. is located at 30701 WOODWARD AVE STE 200, ROYAL OAK, MI, 48073. Phone: (248) 548-2114.
What is WARREN FIELDS, M.D.'s NPI number?
WARREN FIELDS, M.D.'s National Provider Identifier (NPI) is 1225158694, issued on 03/30/2007.
How many Critical Care Medicine (Internal Medicine) Physician providers are there in the US?
There are 6,631 Critical Care Medicine (Internal Medicine) Physician providers across 53 states in the US. The average Critical Care Medicine (Internal Medicine) Physician provider writes 1,069 Medicare Part D claims per year.
What drugs does WARREN FIELDS, M.D. prescribe most often?
Based on 2023 Medicare Part D data, WARREN FIELDS, M.D.'s most frequently prescribed drugs include Albuterol Sulfate Hfa, Prednisone, Trelegy Ellipta. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does WARREN FIELDS, M.D. accept Medicare?
WARREN FIELDS, M.D. appears in CMS Medicare data with 1,901 Part D claims and 324 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify WARREN FIELDS, M.D.'s credentials?
WARREN FIELDS, M.D.'s NPI is 1225158694 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