Dr. Mark Barrett Walker , MD
Ophthalmology • Renton, WA
1300 Sw 7th St, #105
Renton, WA 980575225
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
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NPI assigned on January 30, 2013; this date does not establish years in practice.
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Published CMS data list 27 Medicare Part D prescriptions, including refills, in 2016.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2016. Published rows only; this is not a quality measure.
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Published Part D records, 2016:
- Prednisolone Acetate — 16 prescription fills, including refills.
- Vigamox (Moxifloxacin Hcl) — 11 prescription fills, including refills.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2016. Drug names come from pharmacy claims. Listing a drug here is not an endorsement or a recommendation.
See the full table · Guide: How to read Medicare Part D prescriber data
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Medicare Part D prescriptions went from 36 in 2015 to 27 in 2016.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2015–2016.
Practice Location & Contact Primary Location
1300 Sw 7th St
#105
Renton, WA 980575225
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
What Public CMS Data Show
Ophthalmology: NPPES taxonomy is a reported classification, not proof of board certification.
30-day fills
29 standardized 30-day fills in 2016
CMS converts prescriptions to 30-day supplies so they can be compared. A 90-day prescription counts as about three 30-day fills.
What this does not show: 30-day fills
It is not a count of patients and not a measure of quality.
Part D drug cost
$2,554 in 2016
The total cost of these prescriptions in 2016, paid by Medicare drug plans, patients and other payers together.
It shows the total spending on drugs this clinician prescribed, not what any one patient paid.
What this does not show: Part D drug cost
A higher cost often reflects the type of medicines a specialty uses. It is not your out-of-pocket cost and not a measure of quality.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2016.
Industry payments (Open Payments)
No Open Payments records are listed for this clinician for 2019–2025.
NPI first issued
2013
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Medicare assignment not listed
CMS data do not show whether this clinician accepts Medicare assignment. This does not mean they do not accept Medicare. Ask the office.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians; Medicare.gov, “Does your provider accept Medicare as full payment?”
No telehealth indicator
CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.
Compared with the same specialty in Renton and Washington
Billing and prescribing volume is not a quality rating.
Medicare Part D
Comparisons use 2024 data. The latest CMS data for Dr. Walker are from 2016.
12 active clinicians are listed under Ophthalmology with a practice address in Renton, WA (523 in Washington).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Renton
0% of these 12 clinicians have the CMS telehealth indicator.
41.7% of these 12 clinicians are listed by CMS as accepting Medicare assignment.
CMS data by year
Changes may reflect reporting, coverage or privacy limits, not changes in care quality.
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Medicare Part D prescriptions
Medicare Part D prescriptions decreased 25% from 36 in 2015 to 27 in 2016.
- 2015: 36
- 2016: 27
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30-day fills
30-day fills decreased 23% from 37 in 2015 to 29 in 2016.
- 2015: 37
- 2016: 29
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Part D drug cost
Part D drug cost went from $860 in 2015 to $2,554 in 2016.
- 2015: $860
- 2016: $2,554
Sources: CMS Medicare Part D Prescribers (2016), CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo · Report an error.
Medicare Part D Prescribing Profile & Medications
Medicare Part D prescriptions filled, including refills, in 2016.
| Brand Name | Generic Name | Prescriptions | Day Supply | Total Cost | Patients |
|---|---|---|---|---|---|
| Prednisolone Acetate | Prednisolone Acetate | 16 | 323 | $894.34 | 15 |
| Vigamox | Moxifloxacin Hcl | 11 | 102 | $1,659.17 | 11 |
Source: CMS Part D by Provider and Drug, 2016; rows below 11 claims omitted by CMS; volume isn’t quality. Privacy limits
Specialties & License Numbers Reported to NPPES
NUCC Taxonomy Code: 207W00000X
An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically trained to diagnose, monitor and medically or surgically treat all ocular and visual disorders. This includes problems affecting the eye and its component structures, the eyelids, the orbit and the visual pathways. In so doing, an ophthalmologist prescribes vision services, including glasses and contact lenses.
NUCC Taxonomy Code: 207W00000X
An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically trained to diagnose, monitor and medically or surgically treat all ocular and visual disorders. This includes problems affecting the eye and its component structures, the eyelids, the orbit and the visual pathways. In so doing, an ophthalmologist prescribes vision services, including glasses and contact lenses.
NUCC Taxonomy Code: 207W00000X
An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically trained to diagnose, monitor and medically or surgically treat all ocular and visual disorders. This includes problems affecting the eye and its component structures, the eyelids, the orbit and the visual pathways. In so doing, an ophthalmologist prescribes vision services, including glasses and contact lenses.
NUCC Taxonomy Code: 207W00000X
An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically trained to diagnose, monitor and medically or surgically treat all ocular and visual disorders. This includes problems affecting the eye and its component structures, the eyelids, the orbit and the visual pathways. In so doing, an ophthalmologist prescribes vision services, including glasses and contact lenses.
NUCC Taxonomy Code: 207W00000X
An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically trained to diagnose, monitor and medically or surgically treat all ocular and visual disorders. This includes problems affecting the eye and its component structures, the eyelids, the orbit and the visual pathways. In so doing, an ophthalmologist prescribes vision services, including glasses and contact lenses.
Additional State Medicaid & Healthcare Payer Identifiers
Career & Practice History
NPI enumerated January 30, 2013.
No changes to the name, practice address, taxonomy or NPI status in this record have been observed in the monthly NPPES data files from January 2017 to August 2026.
NPI Administrative Meta
Other Ophthalmology Specialists in Renton
- Dr. Michael Waxman, MD
- Dr. Jamison Ridgeley, MD
- Dr. Silvia Mckevitt, MD
- Dr. Kenneth Fung, MD, MBA
- Dr. Samaneh Davoudimoghaddam, MD
- Dr. Jeanne Cubanski, MD
Mailing Address
333 11th Ave W
Kirkland, WA 980335313
Phone: 4258302707