Quick answers
- Does Louis W. Mastrian accept Medicare assignment?
- Medicare's clinician data says Louis W. Mastrian may accept Medicare assignment (as of October 2, 2026). Ask the office whether they accept it for your visit.
- How many Medicare patients does Louis W. Mastrian see?
- In 2024, CMS data shows 103 Original Medicare patients and 220 services for Louis W. Mastrian. This counts Original Medicare only and measures volume, not quality.
- What is Louis W. Mastrian's NPI number?
- 1255314043. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Louis W. Mastrian, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 103 |
|---|---|
| Services billed to Medicare | 220 |
| Different services or procedures | 15 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)73 services
- Imaging of optic nerve (92133)27 services
- Exam of visual field with extended testing (92083)24 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)24 services
- Measurement of retinal and optic nerve function (92273)22 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High blood pressure72%
- High cholesterol72%
- Arthritis51%
- Anxiety32%
- Diabetes26%
- Ischemic heart disease25%
Practice locations
Addresses where Louis W. Mastrian is enrolled with Medicare (CMS data updated October 2, 2026).
- 490 N Kerrwood Dr, Suite 203Hermitage, PA 16148 (724) 342‑2733
Group practices
Medicare enrollment lists Louis W. Mastrian as a member of this group (CMS data updated October 2, 2026).
- Mastrian Eyecare, LLC3 clinicians in the group
Specialties
- Optometryprimary
Other optometrists in Hermitage
Clinicians with the same Medicare primary specialty in Hermitage, PA — not a recommendation.
Other clinicians in Mastrian Eyecare, LLC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | OD |
|---|---|
| Optometry school | University Of Missouri St Louis - School Of Optometry |
| Graduation year | 1990 (36 years since optometry school) |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1255314043 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians