2026 NPPES data Internal Medicine Physician NPI 1871609354 MD
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CATHERINE BAKER, MD

Internal Medicine Physician in LEMONT, Illinois. 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
4K
Medicare Part D claims · 231 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
86%
generic claims · 14% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$380.08
20 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: CATHERINE BAKER, MD is a Internal Medicine Physician ([object Object]) practicing in LEMONT, Illinois with a Medicare Part D prescribing footprint of 4K claims across 231 beneficiaries — 14% brand-name prescribing . Industry payments of $380.08 across 20 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: CATHERINE BAKER, MD filed 3,500 Medicare Part D claims in 2023 across LEMONT, Illinois. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

CATHERINE BAKER, 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).

CATHERINE BAKER, MD at a glance

Quality data not reported

NPI registry status

Active

Issued 08/21/2006

NPI 1871609354

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

3,500 29% 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

Internal Medicine Physician share within Illinois

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

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).

CATHERINE BAKER, MD is a Internal Medicine Physician provider practicing in LEMONT, Illinois, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1871609354. 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.

CATHERINE BAKER, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 15505 127TH ST, LEMONT, IL, 60439, with a listed phone of (630) 257-2265. NPI 1871609354 was issued on 08/21/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what BAKER 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 3,500 prescription claims written by this provider, covering 231 Medicare beneficiaries and totaling roughly $409K in drug spend, split 14% brand-name and 86% generic by claim count, with an opioid prescribing rate of 1.9%. 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

15505 127TH ST
LEMONT, IL 60439

Provider Details

NPI 1871609354
Specialty Internal Medicine Physician
Credentials MD
Gender Female
NPI Issued 08/21/2006

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 CATHERINE BAKER, MD. Source: openpaymentsdata.cms.gov.

Total received

$380

Largest payer

Lilly USA, LLC

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 — 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 CATHERINE BAKER, MD. To verify CATHERINE BAKER, MD'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 · Typical

CATHERINE BAKER, MD — brand share 14.0%
Specialty average (est.)

14% brand-name claims vs 86% generic, on 3,500 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.

3,500
Total Claims
$409K
Total Drug Cost
231
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
8,176
Total Day Supply
239,156
Brand vs Generic
14% brand / 86% generic
Brand Drug Cost
$339K
Generic Drug Cost
$66K
Opioid Claims
65 (1.9% rate)
Antibiotic Claims
73

Patient Demographics

Average Patient Age
75.8 years
Avg HCC Risk Score
1.07
Gender Split
70% female / 30% male
Age Distribution
<65: 12, 65-74: 85, 75-84: 99, 85+: 35

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Atorvastatin Calcium
278
Lisinopril
221
Levothyroxine Sodium
171
Amlodipine Besylate
158
Metformin Hcl
139
Gabapentin
108
Losartan Potassium
91
Pantoprazole Sodium
85
Simvastatin
80
Alendronate Sodium
74

* 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 CATHERINE BAKER, 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

CATHERINE BAKER, MD's 3,500 claims are above 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 BAKER.

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

Frequently Asked Questions

What is CATHERINE BAKER, MD's specialty?
CATHERINE BAKER, MD specializes in Internal Medicine Physician and practices in LEMONT, Illinois. Credentials: MD.
How much does CATHERINE BAKER, MD prescribe under Medicare Part D?
In 2023, CATHERINE BAKER, MD wrote 3,500 Medicare Part D claims totaling $409K in drug costs for 231 beneficiaries.
Where is CATHERINE BAKER, MD located?
CATHERINE BAKER, MD is located at 15505 127TH ST, LEMONT, IL, 60439. Phone: (630) 257-2265.
What is CATHERINE BAKER, MD's NPI number?
CATHERINE BAKER, MD's National Provider Identifier (NPI) is 1871609354, issued on 08/21/2006.
Does CATHERINE BAKER, MD prescribe more brand-name or generic drugs?
CATHERINE BAKER, MD's prescribing is 14% brand-name and 86% generic drugs by claim count, with $339K in brand drug costs.
Does CATHERINE BAKER, MD prescribe opioids?
Yes, CATHERINE BAKER, MD had 65 opioid claims in 2023 with an opioid prescribing rate of 1.9%.
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 CATHERINE BAKER, MD prescribe most often?
Based on 2023 Medicare Part D data, CATHERINE BAKER, MD's most frequently prescribed drugs include Atorvastatin Calcium, Lisinopril, Levothyroxine Sodium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CATHERINE BAKER, MD accept Medicare?
CATHERINE BAKER, MD appears in CMS Medicare data with 3,500 Part D claims and 231 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CATHERINE BAKER, MD's credentials?
CATHERINE BAKER, MD's NPI is 1871609354 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