2026 NPPES data Internal Medicine Physician NPI 1992454284 MD, MPH
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Brett Slajus, MD, MPH

Internal Medicine Physician in Maywood, Illinois. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers — including 172,858 in Internal Medicine Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration — see our methodology.

Federal data — no proprietary rating. We show these CMS records as-is — no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
276
Medicare Part D claims · 37 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
96%
generic claims · 4% brand-name · higher generic rates reduce patient out-of-pocket costs
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Brett Slajus, MD, MPH filed 276 Medicare Part D claims in 2023 as a Internal Medicine Physician in Maywood, Illinois, prescribing 96% generic.

276
Part D claims, 2023
96%
generic prescribing

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.

Brett Slajus, MD, MPH's Medicare Part D volume vs every U.S. prescriber

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

276 49th percentile higher than 49% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). This entry sits in this band. 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-eligible specialty (heuristic — not verified)

Brett Slajus, MD, MPH 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 Brett Slajus, MD, MPH?

Quality data not reported

NPI registry status

Active

Issued 03/22/2022

NPI 1992454284

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

276 90% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Illinois

How Internal Medicine Physician compares to other specialties among Illinois providers

Illinois providers

Largest specialties in Illinois (% of in-state providers)

Clinical Social Worker — 5.2%Clinical Social Worker5.2%Physical Therapist — 5%Physical Therapist5%Mental Health Counselor — 4.5%Mental Health Counselor4.5%Speech-Language Pathologist — 4.2%Speech-Language Pathologist4.2%Student in an Organized Health Care Education/Training Program — 4.2%Student in an Organized Health Care Education/Training Program4.2%Pharmacist — 4.1%Pharmacist4.1%Internal Medicine Physician — 3.6%Internal Medicine Physician3.6%
Largest specialties in Illinois (% of in-state providers)

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).

Brett Slajus, MD, MPH appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD, MPH credentials at 2160 S 1ST AVE, Maywood, IL, 60153, with a listed phone of (888) 584-7888. NPI 1992454284 was issued on 03/22/2022. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Slajus 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 276 prescription claims written by this provider, covering 37 Medicare beneficiaries and totaling roughly $19K in drug spend, split 4% brand-name and 96% 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.

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

2160 S 1ST AVE
Maywood, IL 60153

Provider Details

NPI 1992454284
Specialty Internal Medicine Physician
Credentials MD, MPH
Gender Male
NPI Issued 03/22/2022

License & disciplinary context — Illinois IDFPR 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 ~42K Illinois medical licensees in 2023 — they are NOT specific to Brett Slajus, MD, MPH. To verify Brett Slajus, MD, MPH's current license status, search the IDFPR public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

106
Total board actions, Illinois 2023
Across 103 cases
2.52
Actions per 1,000 licensees
Illinois statewide rate
probation
Most common action type
38 cases

IDFPR 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 Illinois disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Generic-heavy

Brett Slajus, MD, MPH — brand share 4.0%
Internal Medicine Physician average

4% brand-name claims vs 96% generic, on 276 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.

276
Total Claims
$19K
Total Drug Cost
37
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
427
Total Day Supply
12,174
Brand vs Generic
4% brand / 96% generic
Brand Drug Cost
$12K
Generic Drug Cost
$8K
Antibiotic Claims
14

Patient Demographics

Average Patient Age
71.8 years
Avg HCC Risk Score
3.51
Gender Split
65% female / 35% male

Top Prescribed Drugs (Medicare Part D)

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

What Brett Slajus, MD, MPH 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
Losartan Potassium
19
Atorvastatin Calcium
16
Acyclovir
13
Metformin Hcl
12
Quetiapine Fumarate
12
Furosemide
11

* 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 Brett Slajus, MD, MPH 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

Brett Slajus, MD, MPH's 276 claims are below the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Illinois

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

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

Before you book an appointment

Use this federal record as your verification checklist, not as a recommendation.

  • Confirm the NPI record is current in the official CMS registry — providers update their own NPPES details, and moves can lag. Verify this NPI
  • Check the active license and any disciplinary history with the Illinois medical board — federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Internal Medicine Physician peer on Medicare volume and prescribing patterns. Compare providers

Medicare Part D and MIPS figures describe practice patterns in federal programs only — they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.

Frequently Asked Questions

What is Brett Slajus, MD, MPH's specialty?
Brett Slajus, MD, MPH specializes in Internal Medicine Physician and practices in Maywood, Illinois. Credentials: MD, MPH.
How much does Brett Slajus, MD, MPH prescribe under Medicare Part D?
In 2023, Brett Slajus, MD, MPH wrote 276 Medicare Part D claims totaling $19K in drug costs for 37 beneficiaries.
Where is Brett Slajus, MD, MPH located?
Brett Slajus, MD, MPH is located at 2160 S 1ST AVE, Maywood, IL, 60153. Phone: (888) 584-7888.
What is Brett Slajus, MD, MPH's NPI number?
Brett Slajus, MD, MPH's National Provider Identifier (NPI) is 1992454284, issued on 03/22/2022.
Does Brett Slajus, MD, MPH prescribe more brand-name or generic drugs?
Brett Slajus, MD, MPH's prescribing is 4% brand-name and 96% generic drugs by claim count, with $12K in brand drug costs.
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 Brett Slajus, MD, MPH prescribe most often?
Based on 2023 Medicare Part D data, Brett Slajus, MD, MPH's most frequently prescribed drugs include Losartan Potassium, Atorvastatin Calcium, Acyclovir. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Brett Slajus, MD, MPH accept Medicare?
Brett Slajus, MD, MPH appears in CMS Medicare data with 276 Part D claims and 37 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Brett Slajus, MD, MPH's credentials?
Brett Slajus, MD, MPH's NPI is 1992454284 with credentials MD, MPH. 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

Compiled from official public sources by the PlainDoctor editorial team.