Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

William Register, DO

Individual provider Internal Medicine Physician · NPI 1912384306

William Register, DO is registered under Critical Care (Intensivists) in Elk Grove Village, Illinois. Graduated from University of North Texas Hsc, College of Osteopathic Med in 2015, 11 years ago. Practices with Alexian Brothers Medical Group Specialty Care, a 23-clinician group and accepts Medicare assignment. Licensed in Illinois and Indiana.

Years since qualifying
11
Trained at
University of North Texas Hsc, College of Osteopathic Med
Licensed in
IL, IN
In the registry since
2015
Specialties on file
3
What do these letters mean?
DO — Doctor of Osteopathic Medicine
A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.

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Practice location Address checks out

800 Biesterfield Rd Ste 510
Elk Grove Village, IL 60007-3367
Phone: (847) 981-3660
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Critical Care Medicine (Internal Medicine) Physician (primary) Taxonomy 207RC0200X · Licence 036155248 (IL)
Internal Medicine Physician Taxonomy 207R00000X · Licence 036155248 (IL)
Hospitalist Physician Taxonomy 208M00000X · Licence 02005686A (IN)

Record details

NPI number1912384306
Entity typeIndividual (Type 1)
GenderMale
Credentials DO
Sole proprietorNo
NPI enumeratedMay 5, 2015
Last updated in NPPESOctober 11, 2024
Certification dateOctober 11, 2024

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyCRITICAL CARE (INTENSIVISTS)
Medical schoolUNIVERSITY OF NORTH TEXAS HSC, COLLEGE OF OSTEOPATHIC MED
Graduated 2015 (11 years in practice)
Group practice Alexian Brothers Medical Group Specialty Care — 23 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations3 on file with Medicare

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients260
Services billed 426 a service is one billed item, such as a visit, a test or a procedure
Average patient age77

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Alexian Brothers Medical Group Specialty Care

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 23 clinicians in the practice; 12 are shown here.

Other providers in Elk Grove Village