Gregory J. Duffner, DDS
- Part D claims, 2024
- 23
- Industry payments
- $94
- Affiliated sites
- 1
- Medical group
- 1
- State license
- 1
- Practice address
- 2158 W 183rd St, Homewood, IL 60430
- Practice phone
- Call (708) 798-4730
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Homewood Oral Surgery
Homewood, Illinois
Find Gregory Duffner's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Gregory J. Duffner is a general practice dentistry in Homewood, Illinois
Gregory Duffner practices at Homewood Oral Surgery in Homewood, Illinois.
Gregory Duffner's NPI, 1225340375, was assigned on July 6, 2010. Gregory Duffner holds Illinois license 019-019782.
- NPI
- 1225340375NPI Registry (opens in a new tab)
- NPI enumeration date
- July 6, 2010
- NPI status
- Active
- Practice phone
- (708) 798-4730
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Practice Data
Gregory J. Duffner practices at Homewood Oral Surgery in Homewood, Illinois
Gregory Duffner's primary practice is Homewood Oral Surgery, at 2158 W 183rd St, Homewood, IL 60430 in Cook County. The practice phone is (708) 798-4730.
- Homewood Oral Surgery2158 W 183rd St, Homewood, IL 60430 · Cook CountyPhone(708) 798-4730
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Gregory J. Duffner is affiliated with 2 sites of care and 1 medical group
Gregory Duffner's primary practice is Homewood Oral Surgery in Homewood, Illinois. Dmand AI also links Gregory Duffner to 1 group practice or clinic and 1 medical group, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Gregory J. Duffner's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Gregory Duffner practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Homewood Oral Surgery | Available with a free account |
| +1 more site and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Gregory J. Duffner is one of 2,353 general practice dentistrys in Illinois
General practice is Gregory Duffner's primary specialty in the NPI Registry, under taxonomy code 1223G0001X. Gregory Duffner is licensed in Illinois.
Specialties and state licenses
- General practice dentistry, IllinoisPrimary
General practice dentistrys near Gregory Duffner
Counts of general practice dentistrys 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
Gregory J. Duffner's patients have a median age of 30
Across all payers, Dmand AI patient panel data puts Gregory Duffner's median patient age at 30, with 50% women.
Gregory Duffner's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 30
Patient panel by sex, all payers
- Women50%
- Men50%
Source: Dmand AI Patient Panel Data
Gregory J. Duffner wrote 23 Medicare Part D claims in 2024
In 2024, Gregory Duffner wrote 23 Medicare Part D claims for 15 patients. 87% of them were for generic drugs.
Gregory Duffner's Part D claims by kind of drug, 2024
- Generic20 claims87%
- Brand-name and other3 claims13%
Drug classes CMS tracks in Gregory Duffner's Part D claims, 2024
- Antibiotics61%14 of 23 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Source: Medicare Part D Prescribers - by Provider (CMS), 2024 data
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Gregory J. Duffner received $94 in industry payments in 2025
CMS Open Payments shows 3 general payments to Gregory Duffner from 3 drug and device companies in 2025. Food and beverage make up the largest share, 100% of the total. Straumann USA LLC paid the most, $40.
Companies that paid Gregory Duffner the most, 2025 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Gregory J. Duffner'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 | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand AI Affiliation Data |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel Data |
| Part D prescribing | Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| 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 Gregory J. Duffner
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Gregory J. Duffner's NPI number?
Gregory J. Duffner's NPI number is 1225340375. It was assigned on July 6, 2010, and it is active in the NPI Registry.
What does Gregory J. Duffner specialize in?
Gregory J. Duffner is a general practice dentistry in Homewood, Illinois. The primary specialty in the NPI Registry is General Practice Dentistry (taxonomy code 1223G0001X).
Where does Gregory J. Duffner practice?
Gregory Duffner practices at 2158 W 183rd St, Homewood, IL 60430. Gregory Duffner's primary practice is Homewood Oral Surgery in Homewood, Illinois. Dmand AI also links Gregory Duffner to 1 group practice or clinic and 1 medical group.
What is Gregory J. Duffner's office phone number?
The practice phone on file for Gregory Duffner is (708) 798-4730.
What is Gregory J. Duffner's medical license number?
Gregory Duffner holds Illinois license 019-019782.
Has Gregory J. Duffner received payments from drug or device companies?
CMS Open Payments shows $94 in general payments to Gregory Duffner from 3 companies from 2025 to 2025. The largest total came from Straumann USA LLC.
How long has Gregory J. Duffner been practicing?
Gregory Duffner's NPI was assigned in 2010.
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