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Edit this profileAt a glance
- 2253 W Mason St, Green Bay, WI 54303
About Dr. Duffy
Mark T. Duffy, MD practices ophthalmology in Green Bay, WI. Mark is a 1992 graduate of University of Illinois College of Med (Chi/Peor/Rock/Chm-Urb). Medicare claims data shows Mark provided 7,281 services to 763 patients. The services billed most often include injection, onabotulinumtoxina, 1 unit, exam of visual field with limited testing, and new patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more. The provider's National Provider Identifier (NPI) is 1235167537.
Factual summary compiled by Guide.md from public records; not written by this provider.
Education & Training
Specialty
Credentials & Licensing
Medicare information
Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.
Contact Information
- (920) 327-7000
- Email not available
Practice Locations
2253 W MASON ST
Green Bay, WI 54303
Conditions Commonly Evaluated or Treated
Within Ophthalmology generally. Availability varies by clinician, training and location — this profile has not been claimed, so nothing here is a personal claim by the provider.
Conditions
Most searched conditions
Cornea and external eye
Eyelid and tear drainage
Refractive and focusing
- Astigmatism
- Eye misalignment (strabismus)
- Farsightedness
- Lazy eye (amblyopia)
- Nearsightedness
- Presbyopia
Retina and vitreous
Eye injuries
Inflammation, neurologic, and orbit
Retina & vitreous
Procedures & services
Most searched procedures
Examination and imaging
Cataract and lens
Corneal procedures
Eye diagnostics
Eye injuries
Eyelid surgery
Eyelid, tear duct, and muscle
Glaucoma
- Glaucoma drainage-device implantation
- Laser peripheral iridotomy
- Minimally invasive glaucoma surgery
- Selective laser trabeculoplasty
Laser eye surgery
Laser procedures
Laser vision correction
Refractive surgery
Tear duct & Orbit
Procedures Most Often Billed to Medicare
7,281 services · 763 patients · 14 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Removal of excessive skin and fat of upper eyelid | Procedure | 15823 |
79 | More often than most peers in Ophthalmology |
| Injection of chemical for paralysis of nerve muscles on side of face | Procedure | 64612 |
56 | As often as other peers in Ophthalmology |
| Dilation of tear drainage opening | Procedure | 68801 |
27 | As often as other peers in Ophthalmology |
| Repair of brow paralysis | Procedure | 67900 |
27 | More often than most peers in Ophthalmology |
| Extensive repair of turning-outward eyelid defect | Procedure | 67917 |
20 | As often as other peers in Ophthalmology |
| Repair of tendon of upper eyelid | Procedure | 67904 |
19 | Less often than most peers in Ophthalmology |
| Extensive repair of turning-inward eyelid defect | Procedure | 67924 |
11 | Less often than most peers in Ophthalmology |
| Shortening or advancement of upper eyelid muscle to correct drooping or paralysis | Procedure | 67903 |
11 | Less often than most peers in Ophthalmology |
| Exam of visual field with limited testing | Treatment | 92081 |
192 | More than most peers in Ophthalmology |
| Injection, onabotulinumtoxina, 1 unit | Drug given | J0585 |
6,497 | More often than most peers in Ophthalmology |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Other eye doctors at this location 7
Same specialty, same street address — most likely the same department or group.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
Other eye doctors in Green Bay 6
Same specialty, same city.
More connections — 23 related providers in 3 groups
Trained at University of Illinois College of Med (Chi/Peor/Rock/Chm-Urb) 8
Other providers in the same specialty who trained at the same institution.
Class of 1992 at University of Illinois College of Med (Chi/Peor/Rock/Chm-Urb) 7
Providers who graduated from the same medical school in the same year.
Also performs Removal of excessive skin and fat of upper eyelid 8
Providers in WI who bill this service to Medicare most often.
Common questions
What does Dr. Duffy specialize in?
Dr. Duffy is an eye doctor in Green Bay, WI. That is the designation recorded for this NPI in the federal registry, where it is listed as “Ophthalmology”.
NPI registry
Where is Dr. Duffy located?
Dr. Duffy is listed at 2253 W Mason St, Green Bay, WI 54303. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
What is Dr. Duffy's phone number?
The number on file is (920) 327-7000. Contact the office directly to confirm availability and scheduling.
NPI registry
What is the NPI for Dr. Duffy?
Dr. Duffy's National Provider Identifier is 1235167537. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
Where did Dr. Duffy go to medical school?
Dr. Duffy attended University of Illinois College of Med (Chi/Peor/Rock/Chm-Urb), graduating in 1992. This comes from the CMS National Downloadable File.
CMS public data
How much experience does Dr. Duffy have?
Dr. Duffy has 34 years experience. Calculated from a graduation year of 1992, reported in the CMS National Downloadable File.
CMS public data
What does Dr. Duffy do most often?
According to Medicare billing data, Dr. Duffy performs procedures including removal of excessive skin and fat of upper eyelid, injection of chemical for paralysis of nerve muscles on side of face and dilation of tear drainage opening; provides treatments such as exam of visual field with limited testing, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Is Dr. Duffy's profile verified?
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Duffy. If this is you, claiming it is free.
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