DR. JONATHAN F WILLIAMS D.0.
NPI 1013195650
Internal Medicine - Gastroenterology in Kenilworth, IL

Q: What is Jonathan Williams's NPI number?

The NPI number for Jonathan Williams is 1013195650. It was assigned to this individual provider in the NPPES registry on February 6, 2008.

Q: What is Jonathan Williams's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Q: When was this NPI record last updated?

The NPPES record for Jonathan Williams was last updated on May 31, 2013. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since February 06, 2008PECOS Enrolled

510 GREEN BAY RD, KENILWORTH, IL 60043(847) 256-3400(847) 256-3412 Get Directions Write a Review

NPPES record last updated: May 31, 2013. Verified against the NPPES registry weekly; last sync: October 25, 2026.

On this page

About Dr. Jonathan F Williams D.0. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. JONATHAN F WILLIAMS D.0. (NPI 1013195650) is an individual gastroenterology provider in Kenilworth, Illinois, licensed in Illinois (036-111829) and active in the NPI registry since February 2008. He is enrolled in Medicare PECOS, is affiliated with Northshore University Healthsystem - Evanston Hospital, and is a graduate of Other (2002).

NPPES Registry Identity

NPI1013195650

Entity TypeIndividualMale

Primary Taxonomy207RG0100X

Provider Legal NameDR. JONATHAN F WILLIAMSCredential: D.0.

Location Address510 GREEN BAY RDKenilworth, IL 60043-1002

Mailing Address510 Green Bay RdKenilworth, IL 60043-1002 · (847) 256-3400 · Fax (847) 256-3412

Phone(847) 256-3400

Fax(847) 256-3412

Sole ProprietorNo

Medical School CMSOtherGraduated 2002

Enumeration DateFebruary 6, 2008

Last NPPES UpdateMay 31, 2013

✔ NPI 1013195650 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians

Taxonomy Code207RG0100X

License✔ Licensed in IL · 036-111829

Definition

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.

510 GREEN BAY RD, Kenilworth, IL 60043

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Other Identifiers 1

Medicare PINK51909IL

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include MercyCare, MercyCare Health Plans.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Jonathan F Williams D.0. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

PECOS PAC ID4981777026

PECOS Enrollment IDI20080722000591, I20200624003402

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

Medicare enrollment records show Jonathan Williams reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Gastroenterology Consultants Of The North Shore

0.1 mi

Gastroenterology

505 PARK DR
Kenilworth, IL 60043

Reassigned Medicare billing, Illinois enrollment
2 clinicians in this Medicare group

NPI 1962403212 (847) 256-8661

Rockford Health Physicians

66 mi

Multi-Specialty

8201 E RIVERSIDE BLVD
Rockford, IL 61114

Reassigned Medicare billing, Illinois enrollment
1,375 clinicians in this Medicare group

NPI 1043242886 (608) 314-2428

Mercy Health System Corporation

78 mi

Multi-Specialty

580 N WASHINGTON ST
Janesville, WI 53548

Reassigned Medicare billing, Wisconsin enrollment
1,155 clinicians in this Medicare group

NPI 1598718603 (608) 741-7630

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 19

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Pathology examination of tissue using a microscope, intermediate complexity 88305

A pathology examination of tissue with intermediate complexity involves studying a small sample of your body tissue under a microscope. This helps in identifying any abnormal cells or signs of disease. It's a detailed process requiring expert analysis to ensure accurate results.

1,049 services452 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

478 services296 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

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.

362 services343 patients

Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43239

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.

269 services263 patients

Special stained specimen slides to examine tissue, initial procedure 88342

This procedure involves the use of specially stained slides to examine tissue samples. The initial process involves obtaining a small tissue sample from your body. This sample is then placed on a slide and stained with special dyes to highlight different structures and elements. The stained slide is then examined under a microscope to help diagnose any potential health issues.

259 services205 patients

Removal of polyps or growths of large bowel using an endoscope with mechanical snare 45385

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.

253 services252 patients

Special stained specimen slides to identify organisms including interpretation and report 88312

This service involves coloring specimen slides in a special way to help identify organisms. The colors make different parts of the organism stand out. Afterward, a detailed interpretation and report on the findings are provided.

196 services177 patients

Biopsy of large bowel using a flexible endoscope 45380

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.

186 services186 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

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.

147 services147 patients

Diagnostic exam of large bowel using a flexible endoscope 45378

This procedure, known as a colonoscopy, involves using a flexible tube with a light and camera to examine the large intestine. It helps detect any abnormalities such as polyps or inflammation. It's a standard procedure to ensure gut health.

136 services136 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

135 services135 patients

Special stained specimen slides to examine tissue, each additional procedure 88341

Special stained specimen slides are used to analyze tissue in detail. In this process, extra procedures may be needed for a more thorough examination. These involve applying special stains to the tissue on slides, enhancing specific elements for closer study.

62 services22 patients

Balloon dilation of esophagus, stomach, and/or upper small bowel using a flexible endoscope, less than 3.0 cm 43249

This procedure involves using a flexible tube with a camera, called an endoscope, to gently expand narrowed areas in your esophagus, stomach, or upper small bowel. A small balloon is inflated, making it easier for food and liquid to pass through. It's safe and effective.

47 services47 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

45 services36 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233

Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.

42 services37 patients

Special stained specimen slides to examine tissue including interpretation and report 88313

Special stained specimen slides are used to examine tissue samples. This involves applying special dyes to the tissue, which helps to highlight certain features under a microscope. The findings are then interpreted and a report is provided. This can aid in diagnosing various health conditions.

26 services19 patients

Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43235

This procedure, known as an upper endoscopy, involves inserting a thin, flexible tube with a camera down the throat to examine the esophagus, stomach, and upper small bowel. It helps diagnose conditions like ulcers or inflammation.

22 services22 patients

Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223

Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.

21 services21 patients

Moderate sedation services provided by the same physician or other qualified health care professional performing a gastrointestinal endoscopic service that sedation supports, requiring the presence of an independent trained observer to assist in the monito G0500

Moderate sedation is a method where a physician uses medication to help you relax during a gastrointestinal endoscopy. An independent trained observer will be present to monitor your vital signs and ensure your safety throughout the procedure. It's a common and safe practice.

14 services14 patients

Hospital Affiliations CMS Care Compare 3

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Northshore University Healthsystem - Evanston Hospital

Acute Care Hospitals · Evanston, IL

5/5 CMS rating

OwnershipVoluntary non-profit - Other

CMS Certification Number140010

Location2650 Ridge AveEvanston, IL 60201 · Cook County

Emergency services Birthing friendly

Swedish Hospital

Acute Care Hospitals · Chicago, IL

2/5 CMS rating

OwnershipVoluntary non-profit - Church

CMS Certification Number140114

Location5145 N California AveChicago, IL 60625 · Cook County

Emergency services Birthing friendly

Mercy Health System Corp

Acute Care Hospitals · Janesville, WI

3/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number520066

Location1000 Mineral Point AveJanesville, WI 53548 · Rock County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 60043 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$138.86 typical visit price

range $60.08 – $183.39

Typical copayment $34.71 (range $15.02 – $45.84)

Most-billed visit code 99204

Established Patient

$105.70 typical visit price

range $18.97 – $148.12

Typical copayment $26.42 (range $4.74 – $37.03)

Most-billed visit code 99214

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

Reported Quality Measures

Colorectal Cancer Screening

Percentage of adults 50-75 years of age who had appropriate screening for colorectal cancer

100%349 patients5/55-star benchmark: 100%

Medication Reconciliation Post-Discharge

The percentage of discharges from any inpatient facility (e.g. hospital, skilled nursing facility, or rehabilitation facility) for patients 18 years and older of age seen within 30 days following discharge in the office by the physician, prescribing…

Patients 65+: 100% · 38 patients

100%38 patients

Pneumococcal Vaccination Status for Older Adults

Percentage of patients 65 years of age and older who have ever received a pneumococcal vaccine

100%615 patients5/55-star benchmark: 100%

Preventive Care and Screening: Body Mass Index (BMI) Screening and Follow-Up Plan

Percentage of patients aged 18 years and older with a BMI documented during the current encounter or during the previous twelve months AND with a BMI outside of normal parameters, a follow-up plan is documented during the encounter or during the previous…

100%635 patients5/55-star benchmark: 100%

Screening for Osteoporosis for Women Aged 65-85 Years of Age

Percentage of female patients aged 65-85 years of age who ever had a central dual-energy X-ray absorptiometry (DXA) to check for osteoporosis

100%257 patients5/55-star benchmark: 98%

Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Other Providers at the Same Location NPPES

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

YOLANDRA L JOHNSON MD

Internal Medicine (Gastroenterology)

510 GREEN BAY RD
KENILWORTH, IL 60043

Cook County (847) 251-8661

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Jonathan Williams's NPI number?

The NPI number for Jonathan Williams is 1013195650. It was assigned to this individual provider in the NPPES registry on February 6, 2008.

Where is Jonathan Williams located?

Jonathan Williams practices at 510 Green Bay Rd, Kenilworth, IL 60043. The listed phone number is (847) 256-3400.

What is Jonathan Williams's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Is Jonathan Williams enrolled in Medicare?

Yes. Jonathan Williams is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Jonathan Williams's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Jonathan Williams reassigns Medicare benefits to 3 organizations: Gastroenterology Consultants Of The North Shore (Kenilworth, IL), Rockford Health Physicians (Rockford, IL) and Mercy Health System Corporation (Janesville, WI). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Jonathan Williams's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Jonathan Williams accept?

Health plans from MercyCare and MercyCare Health Plans list Jonathan Williams as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Jonathan Williams affiliated with any hospitals?

According to CMS data, Jonathan Williams is affiliated with Northshore University Healthsystem - Evanston Hospital, Swedish Hospital and Mercy Health System Corp.

When was this NPI record last updated?

The NPPES record for Jonathan Williams was last updated on May 31, 2013. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.