Dr. Gregory S. Granzeier, DO
- Medicare services, 2024
- 12
- Medicare patients, 2024
- 38
- Part D claims, 2024
- 46
- Hospital affiliations
- 2
- Industry payments
- $65
- Practice address
- 2400 North Rockton Avenue, Rockford, IL 61103
- Practice phone
- Call (815) 968-6861
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Granzeier's professional email, personal email and mobile number
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Dr. Gregory S. Granzeier is an OB-GYN in Rockford, Illinois
Dr. Granzeier practices at Javon Bea Hospital-Riverside in Rockford, Illinois, part of Mercyhealth.
Dr. Granzeier's NPI, 1134239320, was assigned on August 30, 2006. Dr. Granzeier graduated from New York College of Osteo Medicine of New York Institute of Technology in 1991. Dr. Granzeier holds Illinois license 036-094024.
- NPI
- 1134239320NPI Registry (opens in a new tab)
- Medicare PAC ID
- 3971563164
- NPI enumeration date
- August 30, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (815) 968-6861
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 61
- Medical school graduation
- 1991
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Gregory S. Granzeier practices at Javon Bea Hospital-Riverside in Rockford, Illinois
Dr. Granzeier's primary practice is Javon Bea Hospital-Riverside, at 2400 North Rockton Avenue, Rockford, IL 61103 in Winnebago County. The practice phone is (815) 968-6861.
- Javon Bea Hospital-Riverside2400 North Rockton Avenue, Rockford, IL 61103 · Winnebago CountyPhone(815) 968-6861
Source: Dmand AI Affiliation Data
Dr. Gregory S. Granzeier is affiliated with 4 sites of care and 1 medical group
Dr. Granzeier's primary practice is Javon Bea Hospital-Riverside in Rockford, Illinois, part of Mercyhealth. The medical group on file is Mercyhealth Physicians. Dmand AI also links Dr. Granzeier to 1 more hospital, 1 group practice or clinic and 1 skilled nursing facility, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Gregory S. Granzeier's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Granzeier practices, 4 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Javon Bea Hospital-Riverside | Available with a free account |
| +3 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
For health IT teams
Dmand AI maps EHR vendors, IT decision makers and buying committees across Mercyhealth and 6.2K+ hospitals, with verified contacts in the same login.
Dr. Gregory S. Granzeier is one of 1,665 OB-GYNs in Illinois
Obstetrics and gynecology is Dr. Granzeier's primary specialty in the NPI Registry, under taxonomy code 207V00000X. Dr. Granzeier is licensed in Illinois.
Specialties and state licenses
- Obstetrics and gynecology, IllinoisPrimary
OB-GYNs near Dr. Granzeier
Counts of OB-GYNs with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Gregory S. Granzeier billed Medicare for 12 services in 2024
CMS data shows 12 Medicare services from Dr. Granzeier across 1 procedure code in 2024, for 38 Medicare patients. Medicare paid $341 for them. Every service was in an office.
Dr. Granzeier's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Other services
- 2023: 02024: 12
- Office and hospital visits
- 2023: 142024: 0100%
Dr. Granzeier compared with the Illinois median for OB-GYNs, 2024
- Dr. Granzeier
- Illinois median
- Medicare services
- 12vs 4875% below
- Medicare patients
- 38vs 4414% below
- Part D claims
- 12vs 2857% below
Medians across 1,360 OB-GYNs in Illinois with Dmand AI profiles that report each measure.
Dr. Granzeier's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Granzeier and other OB-GYNs in Illinois.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Gregory S. Granzeier treated 38 Medicare patients in 2024, average age 68
CMS counts 38 Medicare patients who saw Dr. Granzeier in 2024. The largest group is 65 to 74, with 22 patients. 61% of them have high blood pressure, and 61% have high cholesterol. Their average risk score is 0.88, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Dr. Granzeier's median patient age at 38, with 95% women.
Dr. Granzeier's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Chronic conditions among Dr. Granzeier's Medicare patients, 2024
- High blood pressure61%
- High cholesterol61%
- Anxiety37%
- Arthritis37%
- Mood disorders32%
- Depression29%
Share of Medicare patients with each condition. A patient can have several.
Dr. Granzeier's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 38
Patient panel by sex, all payers
- Women95%
- Men5%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Gregory S. Granzeier wrote 46 Medicare Part D claims in 2024
In 2024, Dr. Granzeier wrote 46 Medicare Part D claims for 21 patients. 80% of them were for generic drugs. CMS names the drug for 12 of them, across 1 drug with 11 or more claims each, at $989 in total drug cost. In 2020, CMS named 11 claims across 1 drug.
Dr. Granzeier's Part D claims by kind of drug, 2024
- Generic37 claims80%
- Brand-name and other9 claims20%
Dr. Granzeier's most prescribed drugs by claims, 2021
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Granzeier's Part D claims, 2024
- Antibiotics24%11 of 46 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2020 to 2021
- 2020
- 2021
- Claims for drugs CMS names
- 2020: 112021: 129%
Drugs named by CMS: 1 in 2021, 1 in 2020.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
How Dr. Gregory S. Granzeier takes part in Medicare
Dr. Granzeier accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Gregory S. Granzeier received $65 in industry payments from 2016 to 2018
CMS Open Payments shows 2 general payments to Dr. Granzeier from 2 drug and device companies from 2016 to 2018. Education make up the largest share, 77% of the total. Pfizer Inc. paid the most, $50.
General payments to Dr. Granzeier by program year, 2016 to 2018
General payments to Dr. Granzeier by kind, 2016 to 2018
- Education$5077%
- Food and beverage$1523%
Companies that paid Dr. Granzeier the most, 2016 to 2018
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Gregory S. Granzeier graduated from New York College of Osteo Medicine of New York Institute of Technology
Dr. Granzeier graduated from New York College of Osteo Medicine of New York Institute of Technology in 1991.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Gregory S. Granzeier's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Gregory S. Granzeier
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Gregory S. Granzeier's NPI number?
Dr. Gregory S. Granzeier's NPI number is 1134239320. It was assigned on August 30, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Gregory S. Granzeier?
Dr. Gregory S. Granzeier is an OB-GYN in Rockford, Illinois. The primary specialty in the NPI Registry is Obstetrics & Gynecology Physician (taxonomy code 207V00000X).
Where does Dr. Gregory S. Granzeier practice?
Dr. Granzeier practices at 2400 North Rockton Avenue, Rockford, IL 61103. Dr. Granzeier's primary practice is Javon Bea Hospital-Riverside in Rockford, Illinois, part of Mercyhealth. Dmand AI also links Dr. Granzeier to 1 hospital, 1 group practice or clinic and 1 skilled nursing facility.
What is Dr. Gregory S. Granzeier's office phone number?
The practice phone on file for Dr. Granzeier is (815) 968-6861.
What is Dr. Gregory S. Granzeier's medical license number?
Dr. Granzeier holds Illinois license 036-094024.
Which hospitals is Dr. Gregory S. Granzeier affiliated with?
Dr. Granzeier practices at Javon Bea Hospital-Riverside in Rockford, Illinois. Dmand AI links Dr. Granzeier to 1 more hospital.
What medical group is Dr. Gregory S. Granzeier part of?
Dr. Granzeier is linked to Mercyhealth Physicians.
Does Dr. Gregory S. Granzeier accept Medicare?
Yes. CMS data shows Dr. Granzeier billed Medicare for 12 services in 2024, and Dr. Granzeier accepts Medicare assignment.
How many Medicare patients does Dr. Gregory S. Granzeier see?
CMS counts 38 Medicare patients who saw Dr. Granzeier in 2024, with an average age of 68.
What services does Dr. Gregory S. Granzeier bill to Medicare?
In 2024, Dr. Granzeier's most billed Medicare services were medicare service (G0101).
Show 4 more questionsShow fewer questions
Where did Dr. Gregory S. Granzeier go to medical school?
Dr. Granzeier graduated from New York College of Osteo Medicine of New York Institute of Technology in 1991.
What drugs does Dr. Gregory S. Granzeier prescribe most?
In 2021 Medicare Part D data, Dr. Granzeier's most prescribed drugs by claims were Estradiol (Twice Weekly).
Has Dr. Gregory S. Granzeier received payments from drug or device companies?
CMS Open Payments shows $65 in general payments to Dr. Granzeier from 2 companies from 2016 to 2018. The largest total came from Pfizer Inc.
How long has Dr. Gregory S. Granzeier been practicing?
Dr. Granzeier graduated from medical school in 1991, 35 years ago.
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