2026 NPPES data Physical Medicine & Rehabilitation Physician NPI 1316031255 M.D.
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GLYN MARSH, M.D.

Physical Medicine & Rehabilitation Physician in WALLA WALLA, Washington. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
190
Medicare Part D claims · 49 beneficiaries · Physical Medicine & Rehabilitation Physician avg: 781
Generic prescribing
78%
generic claims · 22% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

GLYN MARSH, M.D. filed 190 Medicare Part D claims in 2023 as a Physical Medicine & Rehabilitation Physician in WALLA WALLA, Washington, prescribing 78% generic.

190
Part D claims, 2023
78%
generic prescribing
Likely
board-certified (heuristic)

Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) — no proprietary rating or editorial opinion is applied.

GLYN MARSH, M.D.'s Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

190 35th percentile higher than 35% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). This entry sits in this band. 200–400: 182,923 prescribers (13%). Above this entry. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source CMS Medicare Part D Prescriber Public Use File · 2023

Board certification likely (heuristic — not verified)

GLYN MARSH, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

What does the federal data show about GLYN MARSH, M.D.?

Quality data not reported

NPI registry status

Active

Issued 10/03/2006

NPI 1316031255

Primary specialty

Physical Medicine & Rehabilitation Physician

Mid-sized

15,306 US NPIs in this specialty

Medicare Part D claims

190 76% vs specialty avg

2023 prescription claims

Specialty avg: 781

Specialty distribution in Washington

How Physical Medicine & Rehabilitation Physician compares to other specialties among Washington providers

Washington providers

Physical Medicine & Rehabilitation Physician share within Washington

1. Physical Medicine & Rehabilitation Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Physical Medicine & Rehabilitation Physician share within Washington

Specialty board-certification context

Estimated specialty board-certified rate — Physical Medicine & Rehabilitation Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Physical Medicine & Rehabilitation Physician ABMS/AOA estimate

Est. board-certified rate (Physical Medicine & Rehabilitation Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Physical Medicine & Rehabilitation Physician) — ABMS / AOA estimate

The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.

Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).

GLYN MARSH, M.D. appears in the CMS NPPES registry as a Physical Medicine & Rehabilitation Physician provider holding M.D. credentials at 301 W POPLAR ST STE 220, WALLA WALLA, WA, 99362, with a listed phone of (509) 897-8959. NPI 1316031255 was issued on 10/03/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what MARSH most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 190 prescription claims written by this provider, covering 49 Medicare beneficiaries and totaling roughly $38K in drug spend, split 22% brand-name and 78% generic by claim count. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Physical Medicine & Rehabilitation Physician is a mid-sized specialty nationwide, with 15,306 enrolled providers across 54 states and an average of 781 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.

Practice Address

301 W POPLAR ST STE 220
WALLA WALLA, WA 99362

Provider Details

NPI 1316031255
Specialty Physical Medicine & Rehabilitation Physician
Credentials M.D.
Gender Male
NPI Issued 10/03/2006

Hospital and facility affiliations

Facilities where GLYN MARSH, M.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

PROVIDENCE HEALTH AND SERVICES - WASHINGTON
WALLA WALLA, WA

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

License & disciplinary context — Washington WMC 2023 annual report

Aggregate state board data only — NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~34K Washington medical licensees in 2023 — they are NOT specific to GLYN MARSH, M.D.. To verify GLYN MARSH, M.D.'s current license status, search the WMC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

88
Total board actions, Washington 2023
Across 85 cases
2.59
Actions per 1,000 licensees
Washington statewide rate
probation
Most common action type
31 cases

WMC publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Washington disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Typical

GLYN MARSH, M.D. — brand share 22.0%
Specialty average (est.)

22% brand-name claims vs 78% generic, on 190 2023 Medicare Part D claims.

The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

190
Total Claims
$38K
Total Drug Cost
49
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
255
Total Day Supply
7,351
Brand vs Generic
22% brand / 78% generic
Brand Drug Cost
$36K
Generic Drug Cost
$3K

Patient Demographics

Average Patient Age
68.0 years
Avg HCC Risk Score
1.25
Gender Split
67% female / 33% male

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What GLYN MARSH, M.D. prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Duloxetine Hcl
73
Topiramate
23
Baclofen
12
Emgality Pen
Galcanezumab-Gnlm
12
Nurtec Odt
Rimegepant Sulfate
12

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Physical Medicine & Rehabilitation Physician Overview

How GLYN MARSH, M.D. fits within the Physical Medicine & Rehabilitation Physician landscape nationally.

15,306
Physical Medicine & Rehabilitation Physician Providers in US
54
States with Physical Medicine & Rehabilitation Physician
781
Avg Claims per Provider

GLYN MARSH, M.D.'s 190 claims are below the specialty average of 781.

Nearby Physical Medicine & Rehabilitation Physician Providers in Washington

Other clinicians with the same primary specialty enrolled in Washington, drawn from the same CMS NPPES roster as MARSH.

Compare Physical Medicine & Rehabilitation Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is GLYN MARSH, M.D.'s specialty?
GLYN MARSH, M.D. specializes in Physical Medicine & Rehabilitation Physician and practices in WALLA WALLA, Washington. Credentials: M.D..
How much does GLYN MARSH, M.D. prescribe under Medicare Part D?
In 2023, GLYN MARSH, M.D. wrote 190 Medicare Part D claims totaling $38K in drug costs for 49 beneficiaries.
Where is GLYN MARSH, M.D. located?
GLYN MARSH, M.D. is located at 301 W POPLAR ST STE 220, WALLA WALLA, WA, 99362. Phone: (509) 897-8959.
What is GLYN MARSH, M.D.'s NPI number?
GLYN MARSH, M.D.'s National Provider Identifier (NPI) is 1316031255, issued on 10/03/2006.
Does GLYN MARSH, M.D. prescribe more brand-name or generic drugs?
GLYN MARSH, M.D.'s prescribing is 22% brand-name and 78% generic drugs by claim count, with $36K in brand drug costs.
How many Physical Medicine & Rehabilitation Physician providers are there in the US?
There are 15,306 Physical Medicine & Rehabilitation Physician providers across 54 states in the US. The average Physical Medicine & Rehabilitation Physician provider writes 781 Medicare Part D claims per year.
What drugs does GLYN MARSH, M.D. prescribe most often?
Based on 2023 Medicare Part D data, GLYN MARSH, M.D.'s most frequently prescribed drugs include Duloxetine Hcl, Topiramate, Baclofen. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does GLYN MARSH, M.D. accept Medicare?
GLYN MARSH, M.D. appears in CMS Medicare data with 190 Part D claims and 49 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify GLYN MARSH, M.D.'s credentials?
GLYN MARSH, M.D.'s NPI is 1316031255 with credentials M.D.. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.

Data Sources

Provider Directory
CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
Specialty Classification
NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
Prescribing Data
CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
Limitations
Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.

See our complete data methodology for details on how we collect and process government data.

Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).

Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology