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

Gary Altwerger, MD

Individual provider Gynecologic Oncology Physician · NPI 1407114630

Gary Altwerger, MD practises Gynecological Oncology in Chicago, Illinois. Qualified in 2012, 14 years ago. Practices with Ahp Specialty Care Nfp, a 31-clinician group, works from 3 locations, accepts Medicare assignment and offers telehealth. Licensed in Illinois.

Years since qualifying
14
Licensed in
IL
In the registry since
2012
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Claim this listing Report a problem Suggest an edit

Practice location Address checks out

5841 S Maryland Ave
Chicago, IL 60637-1443
Phone: (888) 824-0200
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (2)

  • 333 Cedar Street, New Haven, CT 06510-3220 — (203) 785-7385
  • 880 W. Central Rd., Arlington Heights, IL 60005-2355 — (847) 618-3800

Specialties & licences

Gynecologic Oncology Physician (primary) Taxonomy 207VX0201X · Licence 036176993 (IL)

Record details

NPI number1407114630
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedApril 25, 2012
Last updated in NPPESJanuary 15, 2026
Certification dateJanuary 15, 2026

Medicare enrollment

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

Medicare specialtyGYNECOLOGICAL ONCOLOGY
Also practisesOBSTETRICS/GYNECOLOGY
Medical schoolOTHER
Graduated 2012 (14 years in practice)
Group practice Ahp Specialty Care Nfp — 31 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations3 on file with Medicare

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Removal of the uterus 1–10 times

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

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 patients88
Services billed 284 a service is one billed item, such as a visit, a test or a procedure
Average patient age74

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.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Travel and Lodging $873 3 payments · travel or lodging paid or reimbursed, such as to attend a conference
Food and Beverage $258 6 payments · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

  • The University Of Chicago Medical Center Hospital · Chicago, IL
  • Yale-New Haven Hospital Hospital · New Haven, CT
  • Uchicago Medicine Adventhealth Bolingbrook Hospital · Bolingbrook, IL
  • Uchicago Medicine Adventhealth Hinsdale Hospital · Hinsdale, IL
  • Uchicago Medicine Adventhealth La Grange Hospital · La Grange, IL

Colleagues at Ahp Specialty Care Nfp

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 31 clinicians in the practice; 12 are shown here.

Other providers in Chicago