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DR. WILLIAM B WEEMS MD
NPI 1003856295
Anesthesiology in Rockford, IL

Active since June 07, 2006PECOS EnrolledAccepts Medicare Assignment
5875 E RIVERSIDE BLVD, ROCKFORD, IL 61114(815) 398-9491(815) 381-7498 Get Directions Write a Review

NPPES record last updated: June 26, 2026. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Sep 3, 2024, Jul 26, 2024 (2 updates tracked since 2024).

About Dr. William B Weems Md NPPES

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

DR. WILLIAM B WEEMS MD (NPI 1003856295) is an individual anesthesiology provider in Rockford, Illinois, licensed in Illinois (036101350) and active in the NPI registry since June 2006. He is enrolled in Medicare PECOS, is affiliated with Presence Saint Joseph Medical Center, and maintains 3 additional practice locations.

NPPES Registry Identity

NPI1003856295
Entity TypeIndividualMale
Primary Taxonomy207L00000X
Provider Legal NameDR. WILLIAM B WEEMSCredential: MD
Location Address5875 E RIVERSIDE BLVDRockford, IL 61114-4937
Mailing AddressPo Box 735263Chicago, IL 60673-5263 · (815) 398-9491 · Fax (815) 381-7498
Phone(815) 398-9491
Fax(815) 381-7498
Sole ProprietorNo
Medical School CMSUniversity Of Chicago, Pritzker School Of MedicineGraduated 1996
Enumeration DateJune 7, 2006
Last NPPES UpdateJune 26, 20262 updates tracked since enumeration
NPPES CertifiedJune 26, 2026
✔ NPI 1003856295 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyAnesthesiologyAllopathic & Osteopathic Physicians
Taxonomy Code207L00000X
License✔ Licensed in IL · 036101350
Definition
An anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an operation or an obstetric or diagnostic procedure. The anesthesiologist assesses the risk of the patient undergoing surgery and optimizes the patient's condition prior to, during and after surgery. In addition to these management responsibilities, the anesthesiologist provides medical management and consultation in pain management and critical care medicine. Anesthesiologists diagnose and treat acute, long-standing and cancer pain problems; diagnose and treat patients with critical illnesses or severe injuries; direct resuscitation in the care of patients with cardiac or respiratory emergencies, including the need for artificial ventilation; and supervise post-anesthesia recovery.
5875 E RIVERSIDE BLVD, Rockford, IL 61114
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Secondary Practice Locations 3

Location 110400 Haligus RdHuntley, IL 60142-9553 · Phone (224) 654-0000 · Fax (224) 654-0000
Location 21425 N Randall RdElgin, IL 60123-2300 · Phone (847) 742-9800
Location 3Centegra Memorial Medical Center, 3701 Doty RoadWoodstock, IL 60098 · Phone (815) 334-3170

Accepted Insurance

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

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

Dr. William B Weems Md 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 ID4486552502
PECOS Enrollment IDI20040806000861
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

9

Medicare enrollment records show William Weems reassigns Medicare billing to 9 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Rockford Health Physicians
2.1 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
Orthomidwest, PLLC
3.5 mi
Orthopaedic Surgery
324 ROXBURY RD
Rockford, IL 61107
  • Reassigned Medicare billing, Illinois enrollment
  • 562 clinicians in this Medicare group
NPI 1730136474 (815) 398-9491
Town Square Anesthesia LLC
31 mi
Anesthesiology
3701 DOTY RD
Woodstock, IL 60098
  • Reassigned Medicare billing, Illinois enrollment
  • 87 clinicians in this Medicare group
NPI 1669471017 (815) 338-2500
Northwestern Medical Faculty Foundation
43 mi
Multi-Specialty
DEPT 5777
Carol Stream, IL 60122
  • Reassigned Medicare billing, Illinois enrollment
  • 4,817 clinicians in this Medicare group
NPI 1346235314 (855) 694-2866
Central Dupage Physician Group
57 mi
Family Medicine
5777 DEPARTMENT
Carol Stream, IL 60122
  • Reassigned Medicare billing, Illinois enrollment
  • 1,664 clinicians in this Medicare group
NPI 1033149844 (630) 933-3300
Advocate Health And Hospitals Corporation
62 mi
Cardiovascular Disease
3825 HIGHLAND AVE, TOWER 2 SUITE 400
Downers Grove, IL 60515
  • Reassigned Medicare billing, Illinois enrollment
  • 4,870 clinicians in this Medicare group
NPI 1285903849 (630) 719-4799
Oak Brook Anesthesiologists, Ltd.
62 mi
Anesthesiology
2425 W 22ND ST, SUITE 101
Oak Brook, IL 60523
  • Reassigned Medicare billing, Illinois enrollment
  • 63 clinicians in this Medicare group
NPI 1881705937 (630) 990-2212
North American Partners In Anesthesia (illinois), LLC
69 mi
Anesthesiology
3 ERIE CT
Oak Park, IL 60302
  • Reassigned Medicare billing, Illinois enrollment
  • 826 clinicians in this Medicare group
NPI 1699032524 (315) 413-5229
Blessing Hospital
186 mi
Rural Health
102 PRAIRE MILLS ROAD
Golden, IL 62339
  • Reassigned Medicare billing, Illinois enrollment
  • 127 clinicians in this Medicare group
NPI 1245392349 (217) 696-4446

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 2

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 of anesthetic agent and/or steroid into thigh nerve (femoral nerve) 64447
This procedure involves injecting a numbing agent and/or steroid into a nerve in your thigh. It's done to alleviate pain or inflammation. A needle will be carefully positioned near the nerve, and the medicine will be administered.
20 services20 patients
Injection of anesthetic agent and/or steroid into other nerve or branch 64450
This procedure involves injecting an anesthetic agent or steroid into a specific nerve or its branch. The goal is to relieve pain by reducing inflammation and numbing the area. It is commonly used for chronic pain management. The process is safe and usually quick.
19 services19 patients

Hospital Affiliations CMS Care Compare 3

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

Presence Saint Joseph Medical Center

Acute Care Hospitals · Joliet, IL
2/5 CMS rating
OwnershipVoluntary non-profit - Church
CMS Certification Number140007
Location333 N Madison StJoliet, IL 60435 · Will County
Emergency services Birthing friendly

Advocate Sherman Hospital

Acute Care Hospitals · Elgin, IL
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number140030
Location1425 North Randall RoadElgin, IL 60123 · Kane County
Emergency services Birthing friendly

Javon Bea Hospital

Acute Care Hospitals · Rockford, IL
3/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number140239
Location8201 E Riverside BlvdRockford, IL 61114 · Winnebago County
Emergency services Birthing friendly

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. LIZA A DAFCHAHI SHIRANI MD
Anesthesiology
5875 E RIVERSIDE BLVD
ROCKFORD, IL 61114
Winnebago County (815) 398-9491
MARIOLA U GRZESZCZYK APRN
Nurse Practitioner
5875 E RIVERSIDE BLVD
ROCKFORD, IL 61114
Winnebago County (815) 398-9491
DR. DOUGLAS JOSEPH PACACCIO DPM
Podiatrist (Foot & Ankle Surgery)
5875 E RIVERSIDE BLVD
ROCKFORD, IL 61114
Winnebago County (815) 398-9491
AMANDA L FOIT NP
Nurse Practitioner
5875 E RIVERSIDE BLVD
ROCKFORD, IL 61114
Winnebago County (815) 398-9491
RYAN C ENKE M.D.
Physical Medicine & Rehabilitation
5875 E RIVERSIDE BLVD
ROCKFORD, IL 61114
Winnebago County (815) 398-9491
DR. VISHRUT P. NAIK MD
Anesthesiology (Pain Medicine)
5875 E RIVERSIDE BLVD
ROCKFORD, IL 61114
Winnebago County (815) 398-9491
ADAM SOLIMAN DO
Anesthesiology
5875 E RIVERSIDE BLVD
ROCKFORD, IL 61114
Winnebago County (815) 398-9491
JOSIE M ORR RNFA
Registered Nurse (Registered Nurse First Assistant)
5875 E RIVERSIDE BLVD
ROCKFORD, IL 61114
Winnebago County (815) 398-9491

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 William Weems's NPI number?

The NPI number for William Weems is 1003856295. It was assigned to this individual provider in the NPPES registry on June 7, 2006.

Where is William Weems located?

William Weems practices at 5875 E Riverside Blvd, Rockford, IL 61114. The listed phone number is (815) 398-9491.

What is William Weems's specialty?

The primary specialty registered for this NPI is Anesthesiology with taxonomy code 207L00000X.

Is William Weems enrolled in Medicare?

Yes. William Weems is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organizations bill Medicare for William Weems's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Weems reassigns Medicare benefits to 9 organizations: Rockford Health Physicians (Rockford, IL), Orthomidwest, PLLC (Rockford, IL), Town Square Anesthesia LLC (Woodstock, IL), Northwestern Medical Faculty Foundation (Carol Stream, IL), Central Dupage Physician Group (Carol Stream, IL) and 4 more organizations, listed in the Medicare section above. 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 William Weems's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does William Weems accept?

Health plans from Ambetter Health and Ambetter Health of Delaware list William Weems 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 William Weems affiliated with any hospitals?

According to CMS data, William Weems is affiliated with Presence Saint Joseph Medical Center, Advocate Sherman Hospital and Javon Bea Hospital.

When was this NPI record last updated?

The NPPES record for William Weems was last updated on June 26, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.