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Dr. Niraj Chandrakant Mahajan , MD

Internal Medicine • Chicago, IL

Active NPI 1285825331 Individual Practitioner Male Practitioner Accepts Medicare assignment
Practice location in NPPES

1653 W Congress Pkwy
Chicago, IL 606123833

Call 3129425000 Location details and other listings
Medical Disclaimer

This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.

Practice Location & Contact Primary Location

Practice Address

1653 W Congress Pkwy

Chicago, IL 606123833

Telephone 3129425000
Organization at the Same NPPES Address or Phone
University Pathologists P C Facility NPI 1003890534

Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.

Other Listings in Public Data

CMS Doctors and Clinicians lists 1 group name: Southern California Permanente Medical Group. See the list

Source: CMS Doctors and Clinicians National Downloadable File, release date unavailable.

Listings do not confirm current availability, employment or a shared ownership network.

Medicare Profile & Education

Source: CMS Doctors and Clinicians National Downloadable File

Graduation Year

1999

30-day fills

1,005 standardized 30-day fills in 2024

CMS converts prescriptions to 30-day supplies so they can be compared. A 90-day prescription counts as about three 30-day fills.

What this does not show: 30-day fills

It is not a count of patients and not a measure of quality.

Part D drug cost

$96,027 in 2024

The total cost of these prescriptions in 2024, paid by Medicare drug plans, patients and other payers together.

What this does not show: Part D drug cost

A higher cost often reflects the type of medicines a specialty uses. It is not your out-of-pocket cost and not a measure of quality.

Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024.

Open Payments general payments, program year 2023

All general payments: $29.15 across 2 records.

By nature of payment

  • Food and Beverage: $29.15 across 2 records.

Reporting-company totals

  • Pulmonx Corporation: $14.66 across 1 record.
  • Janssen Pharmaceuticals, Inc: $14.49 across 1 record.

A reported payment does not necessarily mean the financial relationship is improper and is not a measure of care quality. Clinicians can review and dispute these records.

See the full table

Source: Calculated by T-MedInfo from CMS Open Payments general-payment records for program year 2023 (published June 30, 2026).

Guide: How to read an Open Payments record

Years since graduation

27 years (graduated 1999)

CMS Doctors and Clinicians data list 1999 as the year this clinician finished professional school.

What this does not show: Years since graduation

It is not the number of years in practice, and more years does not mean better care.

Source: CMS Doctors and Clinicians National Downloadable File.

NPI first issued

2007

The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.

What this does not show: NPI first issued

NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.

Source: CMS NPPES NPI Registry.

Accepts Medicare assignment

CMS data list this clinician as accepting Medicare assignment. This means agreeing to take the Medicare-approved amount as full payment for covered services.

Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.

Source: CMS Doctors and Clinicians; Medicare.gov, “Does your provider accept Medicare as full payment?”

Guide: What Medicare assignment means

No telehealth indicator

CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.

Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.

Guide: How Medicare covers telehealth

Enrolled in Medicare (PECOS)

Dr. Mahajan has a Medicare enrollment record in PECOS, the CMS system clinicians use to enroll so they can bill Medicare or order services for people with Medicare.

It does not show whether the clinician accepts assignment, is in your plan's network, or is taking new patients.

Source: CMS Medicare Fee-For-Service Public Provider Enrollment (PECOS); CMS Order and Referring file.

Guide: What Medicare enrollment (PECOS) means

Can order Medicare-covered services

CMS lists Dr. Mahajan as eligible to order or refer Medicare Part B clinical laboratory and imaging services, durable medical equipment (DME) and home health services for people with Medicare.

What this does not show: Can order Medicare-covered services

It does not mean the clinician offers these services directly.

Source: CMS Medicare Fee-For-Service Public Provider Enrollment (PECOS); CMS Order and Referring file.

Guide: What ordering and referring status means

Compared with the same specialty in Chicago and Illinois

Billing and prescribing volume is not a quality rating.

Medicare Part D prescriptions

Close to the middle for clinicians listed under Internal Medicine in Chicago, IL (2024, 1,269 clinicians with data). Median for this group: 474. Middle half: 74 to 2,358.

Close to the middle for clinicians listed under Internal Medicine in Illinois (2024, 3,755 clinicians with data). Median for this group: 1,030. Middle half: 99 to 4,658.

Part D drug cost

A higher Part D drug cost than 60% of clinicians listed under Internal Medicine in Chicago, IL (2024, 1,269 clinicians with data). Median for this group: $40,678. Middle half: $1,543 to $232,098.

Close to the middle for clinicians listed under Internal Medicine in Illinois (2024, 3,755 clinicians with data). Median for this group: $78,716. Middle half: $2,604 to $371,507.

2,870 active clinicians are listed under Internal Medicine with a practice address in Chicago, IL (7,245 in Illinois).

Addresses are self-reported to NPPES and may be out of date.

Telehealth indicator in Chicago

13.3% of these 2,870 clinicians have the CMS telehealth indicator.

38.5% of these 2,870 clinicians are listed by CMS as accepting Medicare assignment.

Sources: CMS Medicare Part D Prescribers (2024), CMS Open Payments (2023), CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.

Text: T-MedInfo · Report an error.

Pharma & Medical Device Financial Disclosures

Payments and other transfers of value that drug and medical device companies reported to CMS Open Payments

Open Payments · Program Year 2023

Program year 2023 (payments made January 1 – December 31, 2023): fewer than 11 records totaling $29.15.

Manufacturer Payment Nature Product Type Amount ($)
Pulmonx Corporation
Food and Beverage
In-kind items and services
CHARTIS CATHETER General $14.66
Janssen Pharmaceuticals, Inc
Food and Beverage
In-kind items and services
TALVEY General $14.49

Source: CMS Open Payments, program year 2023, released June 30, 2026.

Medicare Part D Prescribing Profile & Medications

Medicare Part D prescriptions filled, including refills, in 2024.

CMS Part D · Data Year 2024
Prescription Year:
Brand Name Generic Name Prescriptions Day Supply Total Cost Patients
Spiriva Respimat Tiotropium Bromide 122 4,496 $44,948.00 31
Wixela Inhub Fluticasone Propion/Salmeterol 106 9,480 $30,851.55 46
Albuterol Sulfate Hfa Albuterol Sulfate 95 6,017 $2,654.29 40
Prednisone Prednisone 85 1,990 $792.79 44
Azelastine Hcl Azelastine Hcl 55 1,472 $964.85 15
Azithromycin Azithromycin 41 1,001 $431.04 23
Pirfenidone Pirfenidone 24 764 $6,313.37 —
Azathioprine Azathioprine 16 996 $612.81 —
Advair Diskus Fluticasone Propion/Salmeterol 16 570 $8,289.17 —
Furosemide Furosemide 15 1,205 $168.71 11

Source: CMS Part D by Provider and Drug, 2024; rows below 11 claims omitted by CMS; volume isn’t quality. Privacy limits

Specialties & License Numbers Reported to NPPES

Self-certified to NPPES: 2021-11-04
Internal Medicine Primary Specialty

NUCC Taxonomy Code: 207R00000X

License # reported to NPPES IL 36114440

A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.

Check License Status with the State Board License numbers are self-reported to NPPES; T-MedInfo does not confirm them against state records. Current status: Illinois Department of Financial and Professional Regulation.
Look Up on State Board Site

Medicare (PECOS) Enrollment & Ordering Eligibility

Source: CMS PECOS
Medicare FFS Enrollment Status Medicare Enrollment on File
CMS Provider Specialty

PRACTITIONER - INTERNAL MEDICINE

Medicare Enrollment ID

I20100114000411

Enrollment State Jurisdiction

CA

PECOS Control ID

0446391213

Medicare Order & Referring Eligibility
Clinical Lab & Imaging (Part B) Eligible
Durable Medical Equipment (DME) Eligible
Home Health Agency (HHA) Eligible
Power Mobility Devices (PMD) Eligible

Sources: CMS Provider Enrollment and Order and Referring. Medicare enrollment is a billing status, not an accreditation or quality rating.

Medicare Group Practice Enrollments

Source: CMS Doctors and Clinicians National Downloadable File

Southern California Permanente Medical Group

10800 Magnolia Ave, Riverside, CA 925053043

Phone: 9513532000

Southern California Permanente Medical Group

27350 Iris Ave, Moreno Valley, CA 925554802

Phone: 8669847483

Southern California Permanente Medical Group

27300 Iris Ave, Moreno Valley, CA 925554802

Phone: 9512430811

Clinicians Sharing This Practice Address or Phone

Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.

17 listed
Heidi Aguilar , CRNA

Nurse Anesthetist, Certified Registered

NPI 1043703796

Certified Registered Nurse Anesthetist

NPI 1063161644

Doctor of Osteopathic Medicine (D.O.)

Keenan Bayrakdar

Internal Medicine - Endocrinology, Diabetes & Metabolism

NPI 1063090207
NPI 1053567263

Doctor of Medicine (M.D.)

Dr. Elizabeth Evans , MD

Internal Medicine - Cardiovascular Disease

NPI 1023699220

Doctor of Medicine (M.D.)

Katherine Janike

Internal Medicine - Gastroenterology

NPI 1063041549

Career & Practice History

NPI enumerated August 05, 2007.

No changes to the name, practice address, taxonomy or NPI status in this record have been observed in the monthly NPPES data files from January 2017 to August 2026.

No reviews have been published yet. Leave a review.

NPI Administrative Meta

NPI Number: 1285825331
Entity Type:
Individual Provider Physician, Nurse Practitioner, or Solo Healthcare Professional (Type 1 NPI)
Enumeration Date: August 05, 2007
Last Update: November 04, 2021
Sole Proprietor: Yes

Other Internal Medicine Providers in Chicago

All Internal Medicine Providers in Chicago

Mailing Address

1448 W Montrose Ave, Apt 2w

Chicago, IL 606135460

About This Data NPPES fields (address, phone, specialty, license) are self-reported and may be outdated; Medicare fields follow the CMS dataset named in each section. Correct directly at NPPES.