DR. CHRISTOPHER GRANT CHAPMAN M.D.
NPI 1235378043
Internal Medicine - Gastroenterology in Chicago, IL

NPI Status: Active since February 18, 2009

Contact Information

1520 W HARRISON ST
CHICAGO, IL
ZIP 60607
Phone: (312) 942-8651

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  • Individual
  • Male
  • Years of Experience 18
  • Internal Medicine
  • Gastroenterology
  • Accepts Insurance
  • Accepts Medicare Approved Payment
  • PECOS Enrolled

About CHRISTOPHER CHAPMAN

This page provides the complete NPI Profile along with additional information for Christopher Chapman, an internist established in Chicago, Illinois with a medical specialization in Internal Medicine, focusing in gastroenterology and more than 18 years of experience. He graduated from Johns Hopkins University School Of Medicine in 2008. The healthcare provider is registered in the NPI registry with number 1235378043 assigned on February 2009. The practitioner's primary taxonomy code is 207RG0100X with license number 036128100 (IL). The provider is registered as an individual and his NPI record was last updated June 2026.

NPI
1235378043
Provider Name
DR. CHRISTOPHER GRANT CHAPMAN M.D.
Gender
Male
Entity Type
Individual
Location Address
1520 W HARRISON ST CHICAGO, IL 60607
Location Phone
(312) 942-8651
Mailing Address
1725 W HARRISON ST STE 206 CHICAGO, IL 60612
Mailing Phone
(312) 942-8651
Medical School Name
JOHNS HOPKINS UNIVERSITY SCHOOL OF MEDICINE
Graduation Year
2008
Is Sole Proprietor?
No
Enumeration Date
02-18-2009
Last Update Date
06-02-2026
Code Navigator

An internist like Christopher Chapman is a physician who has completed an internal medicine residency and is board-certified or board-eligible in an internist specialty. Internists are trained to care for adults of all ages for many different medical conditions. An internist typically monitors chronic physical conditions, identifies acute diseases, provides family planning, provides counseling about wellness and disease prevention, etc.

Location Map

Specialty - Primary Taxonomy

The NPI enumerator requires providers to submit at least one taxonomy code. A taxonomy code is a unique 10-character code that describes the healthcare provider type, classification, and the area of specialization. There could be only one primary taxonomy code per NPI record. For individual NPIs the license data is associated to the taxonomy code.

Classification

Internal Medicine Gastroenterology

Taxonomy Code
207RG0100X
Type
Allopathic & Osteopathic Physicians
License No.
036128100
License State
IL
Taxonomy Description
An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs.

Secondary Taxonomies

The provider has reported to the NPI enumerator additional taxonomy codes. Multiple taxonomy codes may represent subspecialties or other areas of specialization the provider maybe licensed to practice.

No. Taxonomy Code Type Classification /
Specialization
License No. (State)
1207RG0100XAllopathic & Osteopathic Physicians

Internal Medicine
Gastroenterology

35.146804 (OH)

Insurance Plans Accepted

According to publicly available information the provider might be accepting the following health plans from these health insurance companies:

  • Complete Gold - EPO
  • Complete Gold + Vision + Adult Dental - EPO
  • Complete Silver - EPO
  • Complete Silver + Vision + Adult Dental - EPO
  • Elite Bronze - EPO
  • Elite Bronze + Vision + Adult Dental - EPO
  • Everyday Bronze - EPO
  • Everyday Bronze + Vision + Adult Dental - EPO
  • Everyday Gold - EPO
  • Everyday Gold + Vision + Adult Dental - EPO
  • Standard Expanded Bronze - EPO
  • Standard Expanded Bronze + Vision + Adult Dental - EPO
  • Standard Gold - EPO
  • Standard Gold + Vision + Adult Dental - EPO
  • Standard Silver - EPO
  • Standard Silver + Vision + Adult Dental - EPO
  • Complete Gold - HMO
  • Complete Gold + Vision + Adult Dental - HMO
  • Elite Bronze - HMO
  • Elite Bronze + Vision + Adult Dental - HMO
  • Elite Gold - HMO
  • Elite Gold + Vision + Adult Dental - HMO
  • Everyday Bronze - HMO
  • Everyday Bronze + Vision + Adult Dental - HMO
  • Everyday Gold - HMO
  • Everyday Gold + Vision + Adult Dental - HMO
  • Focused Silver - HMO
  • Focused Silver + Vision + Adult Dental - HMO
  • Standard Expanded Bronze - HMO
  • Standard Expanded Bronze + Vision + Adult Dental - HMO
  • Standard Gold - HMO
  • Standard Gold + Vision + Adult Dental - HMO
  • Standard Silver - HMO
  • Standard Silver + Vision + Adult Dental - HMO
  • Clear Gold - EPO
  • Clear Gold + Vision + Adult Dental - EPO
  • Complete Gold - EPO
  • Complete Gold + Vision + Adult Dental - EPO
  • Elite Silver - EPO
  • Elite Silver + Vision + Adult Dental - EPO
  • Everyday Bronze - EPO
  • Everyday Bronze + Vision + Adult Dental - EPO
  • Focused Silver - EPO
  • Focused Silver + Vision + Adult Dental - EPO
  • Principal Bronze HSA - EPO
  • Principal Bronze HSA + Vision + Adult Dental - EPO
  • Standard Expanded Bronze - EPO
  • Standard Expanded Bronze + Vision + Adult Dental - EPO
  • Standard Gold - EPO
  • Standard Gold + Vision + Adult Dental - EPO
  • Standard Silver - EPO
  • Bronze 7500 $25 Generic Drugs - HMO
  • Bronze 7500 $25 Generic Drugs + Adult Vision & Fitness - HMO
  • Core Gold 1500 $10 Generic Drugs - HMO
  • Core Gold 1500 $10 Generic Drugs + Adult Vision & Fitness - HMO
  • Diabetes Gold 3000 $0 Chronic Care Drugs & Services - HMO
  • Diabetes Gold 3000 $0 Chronic Care Drugs & Services + Adult Vision & Fitness - HMO
  • Diabetes Silver 5000 $0 Chronic Care Drugs & Services - HMO
  • Diabetes Silver 5000 $0 Chronic Care Drugs & Services + Adult Vision & Fitness - HMO
  • Gold 2000 $15 Generic Drugs - HMO
  • Gold 2000 $15 Generic Drugs + Adult Vision & Fitness - HMO
  • HDHP Preventive Silver 5500 $0 Chronic Care Drugs - HMO
  • Healthy Heart Gold 3000 $0 Chronic Care Drugs & Services - HMO
  • Healthy Heart Gold 3000 $0 Chronic Care Drugs & Services + Adult Vision & Fitness - HMO
  • Healthy Heart Silver 5000 $0 Chronic Care Drugs & Services - HMO
  • Healthy Heart Silver 5000 $0 Chronic Care Drugs & Services + Adult Vision & Fitness - HMO
  • Low Premium Bronze 10600 $25 Generic Drugs - HMO
  • Low Premium Bronze 10600 $25 Generic Drugs + Adult Vision & Fitness - HMO
  • Low Premium Silver 6200 $3 Generic Drugs - HMO
  • Low Premium Silver 6200 $3 Generic Drugs + Adult Vision & Fitness - HMO
  • Silver 6000 $20 Generic Drugs - HMO
  • Bronze Classic 4700 - HMO
  • Bronze Classic Standard - HMO
  • Bronze Elite + PCP Saver Plus - HMO
  • Bronze Simple Breathe Easy with Enhanced COPD Benefits - HMO
  • Bronze Simple Chronic Care CKM - HMO
  • Bronze Simple Diabetes - HMO
  • Gold Classic - HMO
  • Gold Classic Standard - HMO
  • Gold Elite Saver Plus - HMO
  • Silver Classic Standard - HMO
  • Silver Elite Saver Plus - HMO
  • Silver Simple Breathe Easy with Enhanced COPD Benefits - HMO
  • Silver Simple Chronic Care CKM - HMO
  • Silver Simple Diabetes - HMO
  • Silver Simple PCP Saver - HMO
  • Silver Simple Women's Health with Menopause Benefits - HMO

*Please verify directly with this provider to make sure your insurance plan is currently accepted.

Medicare Participation & PECOS Enrollment Status

Christopher Chapman is registered with Medicare and accepts claims assignment, this means the provider accepts the approved amount for the cost of rendered services as full payment. Participating providers may not charge beneficiaries more than the approved amount for their services. Please keep in mind that beneficiaries still have to pay a coinsurance or copayment amount for a visit or service.

Christopher Chapman is enrolled in PECOS and is eligible to order or refer health care services for Medicare patients. The provider is eligible to order or refer: Part B Clinical Laboratory and Imaging, Durable Medical Equipment (DME), a Home Health Agency (HHA) and Power Mobility Devices.

What is PECOS?
PECOS is the online Medicare enrollment management system or Provider, Enrollment, Chain and Ownership System. The PECOS system is a database of providers who have registered with CMS as providers or suppliers. PECOS is the primary source of information about verified Medicare professionals. Providers that want to participate in this program need to enroll in PECOS with their NPI number to avoid denied claims.

  • Is the provider registered in PECOS? Yes

  • PECOS PAC ID: 7719155357

    What is the PECOS Associate Control ID?
    A PAC ID is a unique 10-digit number assigned to an individual or organization healthcare provider in PECOS. The PAC ID is used to link together all the provider information, like tax identification numbers and organizational names. A PAC ID can be connected to multiple Enrollment IDs if an individual or organization has enrolled in PECOS more than once.

  • PECOS Enrollment ID: I20110726000199, I20260130000568

    What is the Provider Enrollment ID?
    The Enrollment ID is a unique alphanumeric 15-digit code assigned to each new provider's PECOS enrollment application. The Enrollment ID is used to link together all the provider enrollment information like enrollment type, state, provider specialty, and reassignment of benefits.

  • Accepts Medicare Assignment? Yes

    What does it mean "accepts medicare assignment"?
    When a provider accepts Medicare assignment, the provider agrees to be paid directly by Medicare and to accept the payment amount approved by Medicare. Additionally, the provider agrees to not bill patients for more than the Medicare deductible and coinsurance amounts.
    A provider who doesn't accept assignment may charge you up to 15% over the Medicare-approved amount. This is known as the limiting charge. You may have to pay this amount, or it may be covered by another insurer.

  • Eligible to Order or Refer Part B Clinical Laboratory and Imaging: Yes

  • Eligible to Order or Refer Durable Medical Equipment (DMEPOS): Yes

  • Eligible to Order or Refer a Home Health Agency (HHA): Yes

  • Eligible to Order or Refer Power Mobility Devices: Yes

Areas of Expertise

The following services and procedures, recently provided to Medicare patients, illustrate the range of care this provider offers. This list reflects the variety of services available to all patients visiting the practice and is based on 2022 Medicare dataset. In general, the more frequently a provider treats specific conditions or performs particular procedures, the more experienced they become in addressing similar patient needs. The provider has delivered many of the services listed below to Medicare patients. Please note that this list does not include services provided to patients who are not covered by Medicare.

Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope

This procedure involves using a thin, flexible tube with a light and camera, known as an endoscope, to examine the esophagus, stomach, and upper part of the small intestine. Small tissue samples are taken for further examination to help diagnose various conditions.

This service was performed 67 times for 58 patients

Biopsy of large bowel using a flexible endoscope

A biopsy of the large bowel using a flexible endoscope is a procedure where a thin, flexible tube with a camera is inserted through the rectum to examine the bowel. If abnormal tissue is found, a small sample is taken for further examination. This helps in diagnosing conditions like inflammation, polyps, or cancer.

This service was performed 33 times for 33 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more

This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.

This service was performed 18 times for 16 patients

Insertion of stent into pancreatic or bile duct using a flexible endoscope

This procedure involves the placement of a tiny tube, known as a stent, into your pancreatic or bile duct. A flexible endoscope, a long, thin instrument with a light and camera, is used. It aids in relieving blockages and improving flow in these ducts.

This service was performed 36 times for 26 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

This service was performed 12 times for 12 patients

Removal of large bowel tissue using a flexible endoscope

This procedure, known as a colonoscopy, involves using a flexible endoscope to examine and potentially remove tissue from the large intestine. The endoscope allows the doctor to view the bowel lining directly and remove any abnormal tissue for further analysis.

This service was performed 15 times for 15 patients

Removal of polyps or growths of large bowel using an endoscope with mechanical snare

This procedure involves using a thin, flexible tube called an endoscope to examine the large bowel. If any abnormal growths or polyps are found, a tool called a mechanical snare is used to remove them. This is a common method to prevent potential health issues.

This service was performed 29 times for 29 patients

Removal of stone or debris from bile or pancreatic duct using a flexible endoscope

This procedure, called an endoscopic retrograde cholangiopancreatography (ERCP), involves using a flexible tube with a camera (endoscope) to locate and remove stones or debris from your bile or pancreatic duct. It's a non-surgical method to clear the ducts, enhancing your digestive health.

This service was performed 31 times for 21 patients

Review by radiologist of image from tube placement into bile duct using an endoscope

This procedure involves a specialist, called a radiologist, examining an image taken during a tube placement into your bile duct. The tube is inserted with the help of a tool called an endoscope. This allows the doctor to check for any issues or abnormalities in your bile duct.

This service was performed 45 times for 29 patients

Ultrasound exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope through mouth

This procedure involves a flexible tube with a camera and ultrasound device, inserted through the mouth to examine the esophagus, stomach, and upper small bowel. It helps diagnose conditions like inflammation, tumors, or other abnormalities.

This service was performed 13 times for 13 patients

Ultrasound guided needle aspiration or biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope

This procedure involves using an ultrasound to guide a needle to specific areas in the esophagus, stomach, or upper small bowel. A flexible endoscope is used to reach these areas. The needle collects a small sample for testing.

This service was performed 19 times for 18 patients

Physician Visit Costs



The typical physician office visit costs for Medicare beneficiaries in this area are: $34.71 for a new patient copayment and $26.42 for an established patient copayment.

The pricing information below displays the copayment minimum, maximum and average amount that patients under Medicare are charged when visiting this provider as a new or established patient. Please keep in mind that these prices are just for reference purposes, and the actual prices charged by the provider might be different.

For patients covered under private health plans the prices below are also useful as healthcare pricing for private insurance is usually established as a function of Medicare prices. Private insurance covered patients should check their individual plans to determine the exact pricing.

The prices below reflect the costs for new and established patients in the 60607 ZIP code area.

New Patients Visit Costs *

The most utilized procedure code for new patients office visits is 99204

  • Average New Patient Price $138.86
  • Minimum New Patient Price $60.08
  • Maximum New Patient Price $183.39
  • Average New Patient Copayment $34.71
  • Minimum New Patient Copayment $15.02
  • Maximum New Patient Copayment $45.84

Established Patients Visit Costs *

The most utilized procedure code for established patients office visits is 99214

  • Average Established Patient Price $105.7
  • Minimum Established Patient Price $18.97
  • Maximum Established Patient Price $148.12
  • Average Established Patient Copayment $26.42
  • Minimum Established Patient Copayment $4.74
  • Maximum Established Patient Copayment $37.03

* The physician office visit costs information is generated by statistical analysis of similar providers in the same geographical area. The pricing information above IS NOT the amount charged by this provider.

Find Provider Hospital Affiliations - Privileges

Doctors and physicians must apply for hospital privileges to treat patients at hospitals. Find out if your doctor has privileges to practice at your preferred hospital by using the hospital affiliation information below based on recent medical claims.

Hospital affiliation is identified through self-reporting data, inpatient, outpatient, physician and ancillary service claims linked by the medical claims NPI number and place of service code. Additionally, to further determine provider hospital affiliation the clinician must have provided services to at least three patients on three different dates in the last 12 months. Christopher Chapman is affiliated with the following medical facilities:

Hospital Name Address Phone Hospital Type Overall Rating
RUSH UNIVERSITY MEDICAL CENTER1653 WEST CONGRESS PARKWAY
CHICAGO, IL 60612
(312) 942-5000Acute Care Hospitals

Reviews for DR. CHRISTOPHER GRANT CHAPMAN M.D.

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NPI NPI Number Validation

How NPI Validation Works

The NPI validation process uses the ISO-standard Luhn algorithm, a mathematical "handshake", to ensure that a provider's 10-digit ID is authentic and free of common typing errors.

To verify the NPI 1235378043, we treat the final digit (3) as the Check Digit—the target answer we need to reach. The process begins by taking the first nine digits and adding a constant value of 24, which accounts for the "80840" prefix required for all U.S. health identifiers. We then double every other digit starting from the right and sum the individual digits of those results together. For this specific NPI, that total comes to 67. The final step is to find the difference between that total and the next multiple of ten (70 - 67 = 3).

Digit-by-digit view

Use the first nine digits for the calculation. Starting from the right, double every other digit. The last digit is the check digit and is not part of the calculation.

Pos 1
1
Doubled → 2
Pos 2
2
Unchanged
Pos 3
3
Doubled → 6
Pos 4
5
Unchanged
Pos 5
3
Doubled → 6
Pos 6
7
Unchanged
Pos 7
8
Doubled → 16 → 1 + 6
Pos 8
0
Unchanged
Pos 9
4
Doubled → 8
Check
3
Target digit
Regular digit Doubled digit Check digit

Step 1: Double every other digit from the right

Starting with the rightmost digit of the first nine digits, double every other value. If doubling creates a two-digit number, add those digits together.

1 → 2 3 → 6 3 → 6 8 → 16 → 7 4 → 8

Step 2: Add all digits plus the NPI constant

Add the transformed values, the unchanged digits, and the constant 24.

2 + 2 + 6 + 5 + 6 + 7 + 1 + 6 + 0 + 8 + 24 = 67

Step 3: Find the amount needed to reach the next multiple of 10

The next multiple of ten after 67 is 70. The difference is the calculated check digit.

70 - 67 = 3
This NPI is valid
The calculated check digit is 3, which matches the last digit of 1235378043.

Other Providers at the Same Location


The following 20 providers are registered at the same or a nearby location.

Nurse Practitioner
1520 W HARRISON ST
CHICAGO, IL 60607
Nurse Practitioner (Family)
1520 W HARRISON ST
CHICAGO, IL 60607
Radiology (Radiation Oncology)
1520 W HARRISON ST
CHICAGO, IL 60607
Psychiatry & Neurology (Neurology)
1520 W HARRISON ST
CHICAGO, IL 60607
Physician Assistant
1520 W HARRISON ST
CHICAGO, IL 60607
Nurse Practitioner
1520 W HARRISON ST
CHICAGO, IL 60607
Internal Medicine (Medical Oncology)
1520 W HARRISON ST
CHICAGO, IL 60607
Nurse Practitioner (Gerontology)
1520 W HARRISON ST
CHICAGO, IL 60607
Nurse Practitioner
1520 W HARRISON ST
CHICAGO, IL 60607
Clinical Exercise Physiologist
1520 W HARRISON ST
CHICAGO, IL 60607
Otolaryngology
1520 W HARRISON ST
CHICAGO, IL 60607
Nurse Practitioner (Primary Care)
1520 W HARRISON ST
CHICAGO, IL 60607
Psychiatry & Neurology (Neurology)
1520 W HARRISON ST
CHICAGO, IL 60607
Neurological Surgery
1520 W HARRISON ST
CHICAGO, IL 60607
Internal Medicine (Hematology)
1520 W HARRISON ST
CHICAGO, IL 60607
Surgery
1520 W HARRISON ST
CHICAGO, IL 60607
Obstetrics & Gynecology (Gynecologic Oncology)
1520 W HARRISON ST
CHICAGO, IL 60607
Surgery (Surgical Oncology)
1520 W HARRISON ST
CHICAGO, IL 60607
Internal Medicine (Hematology & Oncology)
1520 W HARRISON ST
CHICAGO, IL 60607
Nurse Practitioner (Family)
1520 W HARRISON ST
CHICAGO, IL 60607

Frequently Asked Questions

The NPI number assigned to this healthcare provider is 1235378043, enumerated as an "individual" on February 18, 2009.

The provider is located at 1520 W HARRISON ST CHICAGO, IL 60607 and the phone number is (312) 942-8651.

Internal Medicine with taxonomy code 207RG0100X and a focus in Gastroenterology.

The provider might be accepting Accepts: Ambetter from Home State Health, Ambetter Health,. Please consult your insurance carrier or call the provider to verify.

Christopher Chapman is affiliated with: RUSH UNIVERSITY MEDICAL CENTER.