Mark Greiner, M.D.
NPI 1194992958 · Ophthalmology Physician · Iowa City, IA
Enrolled with Medicare as Practitioner - Ophthalmology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Greiner, M.D. is a Ophthalmology Physician provider in Iowa City, IA (NPI 1194992958).
Provider details
- NPI number
- 1194992958
- Entity type
- Individual
- Primary specialty
- Ophthalmology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
18 yrs in NPPES registry
- Profile completeness28% of score
83% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
2,031 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Ultrasound Scan of Cornea to Determine Thickness76514 | 568 | $7 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 559 | $89 |
| Imaging of Front Third of Eye Using a Special Microscope92286 | 186 | $20 |
| Ct Scan of Cornea92025 | 180 | $18 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 74 | $61 |
| Transplantation of Outer Layer of Corneal Tissue65756 | 62 | $1,072 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 19 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Prednisolone Acetate | 331 | 173 |
| Fluorometholone | 273 | 103 |
| Valacyclovir Hclbrand: Valacyclovir | 134 | 54 |
| Moxifloxacin Hclbrand: Moxifloxacin | 107 | 54 |
| Medroxyprogesterone Acetate | 58 | — |
| Doxycycline Hyclate | 51 | 17 |
| Timolol Maleate | 40 | 17 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2008-05-12
- Last updated
- 2012-08-16
Frequently asked questions
- What is Mark Greiner's NPI number?
- Mark Greiner's National Provider Identifier (NPI) is 1194992958, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Greiner's specialty?
- Mark Greiner is listed in the NPPES registry with a primary specialty of Ophthalmology Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Greiner located?
- Mark Greiner's practice location on file with NPPES is 200 Hawkins Dr, Iowa City, IA 52242-1009.
- What is Mark Greiner's phone number?
- The practice phone number listed in the NPPES registry for Mark Greiner is (319) 356-2861.
- Does Mark Greiner accept Medicare?
- Mark Greiner is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Greiner's NPI active?
- Yes — Mark Greiner's NPI (1194992958) is active in the NPPES registry as of the last update on 2012-08-16.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.