ROBERT R MCWILLIAMS M.D.
NPI 1487633962
Internal Medicine - Medical Oncology in Peoria, IL

Q: What is Robert Mcwilliams's NPI number?

The NPI number for Robert Mcwilliams is 1487633962. It was assigned to this individual provider in the NPPES registry on January 12, 2006.

Q: What is Robert Mcwilliams's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Medical Oncology, with taxonomy code 207RX0202X.

Q: When was this NPI record last updated?

The NPPES record for Robert Mcwilliams was last updated on February 25, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 8 months 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 January 12, 2006PECOS EnrolledAccepts Medicare Assignment

530 NE GLEN OAK AVE, PEORIA, IL 61637(309) 655-2000 Get Directions Write a Review

NPPES record last updated: February 25, 2026. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Dec 8, 2025, Nov 19, 2025, Nov 13, 2025 and 3 more (6 updates tracked since 2017).

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About Robert R Mcwilliams M.d. NPPES

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

ROBERT R MCWILLIAMS M.D. (NPI 1487633962) is an individual medical oncology provider in Peoria, Illinois, licensed in Illinois (036131628) and active in the NPI registry since January 2006. He is enrolled in Medicare PECOS, is affiliated with St Mary Medical Center, and maintains a secondary practice location in Rochester.

NPPES Registry Identity

NPI1487633962

Entity TypeIndividualMale

Primary Taxonomy207RX0202X

Provider Legal NameROBERT R MCWILLIAMSCredential: M.D.

Location Address530 NE GLEN OAK AVEPeoria, IL 61637-0001

Mailing Address30791 High RdFountain, MN 55935-5147 · (507) 358-5982

Phone(309) 655-2000

Sole ProprietorNo

Medical School CMSGeorge Washington University School Of MedicineGraduated 1997

Enumeration DateJanuary 12, 2006

Last NPPES UpdateFebruary 25, 20266 updates tracked since enumeration

NPPES CertifiedFebruary 25, 2026

✔ NPI 1487633962 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtyInternal Medicine · Medical OncologyAllopathic & Osteopathic Physicians

Taxonomy Code207RX0202X

Licenses✔ Licensed in IL · 036131628✔ Licensed in MN · 44014

Definition

An internist who specializes in the diagnosis and treatment of all types of cancer and other benign and malignant tumors. This specialist decides on and administers therapy for these malignancies as well as consults with surgeons and radiotherapists on other treatments for cancer.

Also ListedInternal MedicineTaxonomy 207R00000X · License 036131628 (IL)

Also ListedInternal Medicine · Hematology & OncologyTaxonomy 207RH0003X · License 44014 (MN)

530 NE GLEN OAK AVE, Peoria, IL 61637

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Secondary Practice Location 1

Location 1200 1st St SWRochester, MN 55905-0001 · Phone (507) 284-2511

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Robert R Mcwilliams M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID2961452396

PECOS Enrollment IDI20050124001040, I20251124000639

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 Robert Mcwilliams reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Osf Multi-Specialty Group

7.4 mi

Internal Medicine

8600 N STATE ROUTE 91
Peoria, IL 61615

Reassigned Medicare billing, Illinois enrollment
2,944 clinicians in this Medicare group

NPI 1922445527 (309) 683-5050

Mayo Clinic

272 mi

Infectious Disease

200 1ST ST SW
Rochester, MN 55905

Reassigned Medicare billing, Minnesota enrollment
6,534 clinicians in this Medicare group

NPI 1114343860 (507) 284-2511

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 24

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.

Injection, nivolumab, 1 mg J9299

Nivolumab is a medication given via injection, often used in cancer treatment. It works by helping your immune system fight the cancer cells. The dosage is measured in milligrams (mg), with 1 mg being a common dose.

3,600 services11 patients

Injection, pembrolizumab, 1 mg J9271

Pembrolizumab is a medication given via injection to help your body's immune system fight certain types of cancer. It's typically administered in a hospital or clinic by a healthcare professional.

3,202 services13 patients

Injection, daratumumab, 10 mg and hyaluronidase-fihj J9144

Daratumumab and hyaluronidase-fihj is an injection administered to treat certain types of blood cancer. The medication works by targeting and killing specific cancer cells. It's often given under the skin to reduce side effects and improve patient comfort.

2,340 services13 patients

Injection, bortezomib, 0.1 mg J9041

Bortezomib (Velcade) is a medication administered through an injection. It's used to treat multiple myeloma and mantle cell lymphoma, types of cancer. It works by blocking certain proteins in cancer cells, slowing their growth.

577 services13 patients

Injection, dexamethasone sodium phosphate, 1 mg J1100

Dexamethasone sodium phosphate is a medication given via injection. It is a type of steroid that helps reduce inflammation and immune responses. It can be used to treat a variety of conditions, such as allergies, skin conditions, arthritis, and more.

372 services36 patients

Injection, palonosetron hcl, 25 mcg J2469

Palonosetron HCL is an injection used to prevent nausea and vomiting caused by chemotherapy. It works by blocking a natural substance (serotonin) in the body that can cause vomiting. This helps improve your comfort during cancer treatment.

300 services30 patients

Injection, ondansetron hydrochloride, per 1 mg J2405

Ondansetron hydrochloride is a medication given via injection to help prevent nausea and vomiting, often due to chemotherapy or surgery. It works by blocking certain chemicals in the body that trigger these symptoms.

240 services26 patients

Injection of additional new drug or substance into vein 96375

This procedure involves introducing a new medication or substance into your bloodstream via a vein. It's typically done using a small needle. The substance can help treat various conditions or assist in diagnostic procedures. It's generally safe and monitored by professionals.

131 services62 patients

Administration of chemotherapy into vein, 1 hour or less 96413

Chemotherapy is a treatment that uses drugs to destroy cancer cells. When administered into a vein, it's often through an IV. This procedure usually lasts 1 hour or less. You may feel a slight pinch as the needle is inserted, but it's generally painless.

97 services92 patients

Injection, fluorouracil, 500 mg J9190

Fluorouracil is a chemotherapy drug, given as an injection to treat various types of cancer. The 500 mg dose helps to stop cancer cells from growing and multiplying. You might feel some side effects, but these are typically manageable.

92 services11 patients

Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215

This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.

82 services67 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.

64 services51 patients

Administration of non-hormonal anti-neoplastic chemotherapy under skin or into muscle 96401

This procedure involves giving anti-cancer drugs, which don't contain hormones, into the muscle or under the skin. These drugs help to stop the growth of cancer cells. The process is usually quick and done by a healthcare professional.

34 services23 patients

Administration of chemotherapy into vein, each additional hour 96415

Chemotherapy is a treatment method that uses drugs to destroy cancer cells. The drugs are administered into a vein, usually in the arm. Each additional hour of chemotherapy allows for more of the medication to enter your bloodstream to fight against the cancer cells.

31 services19 patients

Administration of additional new drug or substance into vein, 1 hour or less 96417

This procedure involves introducing a new drug or substance into your vein, typically via an IV drip. It lasts for an hour or less. This method allows the substance to quickly reach your bloodstream, ensuring rapid and effective treatment.

28 services24 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.

24 services20 patients

Unclassified drugs J3490

Unclassified drugs are medications that don't fit into an existing category or class due to their unique properties or uses. They may be used for various conditions and their effects may differ widely. Always ask your healthcare provider for more information about these drugs.

19 services15 patients

Injection, diphenhydramine hcl, up to 50 mg J1200

Diphenhydramine HCL injection is a medicine given to alleviate symptoms of allergies, colds, or hay fever. It can also help with motion sickness and certain symptoms of Parkinson's disease. Up to 50 mg may be administered depending on your condition.

18 services17 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.

17 services17 patients

New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more 99205

This is a first-time patient visit where a healthcare professional spends 60-74 minutes with you. It involves a comprehensive evaluation, including your medical history and current health condition. They'll also advise on preventive health measures and formulate a treatment plan if needed.

17 services17 patients

Infusion into a vein for therapy, prevention, or diagnosis, additional sequential infusion, 1 hour or less 96367

This procedure involves injecting fluids or medication directly into your vein. It's used for treatment, prevention, or diagnosis. An additional sequential infusion may be given within an hour if needed. This helps to ensure the medicine is distributed effectively in your body.

15 services12 patients

Injection of drug or substance under skin or into muscle 96372

This procedure involves administering medication directly under the skin or into a muscle. A small needle is used to inject the drug, allowing it to be absorbed quickly into the bloodstream. It's a common method for delivering a variety of medications.

15 services14 patients

Administration of hormonal anti-neoplastic chemotherapy under skin or into muscle 96402

This procedure involves the injection of hormone-based anti-cancer drugs under the skin or into a muscle. These medications help to slow down or stop the growth of certain types of cancer cells. The process is usually quick and can be performed in a clinic or hospital.

15 services11 patients

Chemotherapy administration, intravenous infusion technique; initiation of infusion in the office/clinic setting using office/clinic pump/supplies, with continuation of the infusion in the community setting (e.g., home, domiciliary, rest home or assisted l G0498

Chemotherapy is a treatment method that uses drugs to destroy cancer cells. In the office, a pump is used to start an intravenous infusion of these drugs. The infusion can then be continued at home or another setting, like a rest home.

11 services11 patients

Hospital Affiliations CMS Care Compare 3

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

St Mary Medical Center

Acute Care Hospitals · Galesburg, IL

3/5 CMS rating

OwnershipVoluntary non-profit - Church

CMS Certification Number140064

Location3333 North SeminaryGalesburg, IL 61401 · Knox County

Emergency services Birthing friendly

Saint Francis Medical Center

Acute Care Hospitals · Peoria, IL

1/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number140067

Location530 NE Glen Oak AvePeoria, IL 61637 · Peoria County

Emergency services Birthing friendly

Mayo Clinic Hospital Rochester

Acute Care Hospitals · Rochester, MN

5/5 CMS rating

OwnershipVoluntary non-profit - Church

CMS Certification Number240010

Location1216 Second Street SouthwestRochester, MN 55902 · Olmsted County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 61637 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

$168.44 typical visit price

range $54.80 – $168.44

Typical copayment $42.11 (range $13.70 – $42.11)

Most-billed visit code 99205

Established Patient

$97.25 typical visit price

range $17.16 – $136.56

Typical copayment $24.31 (range $4.29 – $34.14)

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.

Referred Medical Equipment & Supplies CMS DME claims

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Capecitabine, oral, 500 mg J8521

Treatment-Treatment - Miscellaneous · category RX029N

3 suppliers11 claims680 services$0.68 avg. paid by Medicare

Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 20

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

DR. HAMID MAHMOOD ZIA M.D

Pathology (Anatomic Pathology & Clinical Pathology)

530 NE GLEN OAK AVE, CENTRAL ILLINOIS PATHOLOGY SC
PEORIA, IL 61637

Peoria County (309) 624-9011

THOMAS JAMES MCMORROW MD

Pediatrics