Marshall Roy Koon, PA-C
Medical Physician Assistant · Apple Valley, CA
Marshall Roy Koon, PA-C is a medical physician assistant with a practice address in Apple Valley, California, and NPI 1982939302, issued on Oct 4, 2009. Check the license (California PA20578, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Marshall Roy Koon
- Credential
- PA-C
- Primary taxonomy
- Medical Physician Assistant 363AM0700X
- License number
- PA20578 CA
Self-reported in NPPES; status is on the state search - Practice location
- 18300 US Highway 18, Apple Valley, CA 92307
- Phone
- (760) 242-2311
- Enumerated
- Oct 4, 2009
- Record last updated
- Oct 4, 2009 (not updated in 17 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
8 nearest medical physician assistant records → All 3,376 in California → Look up another NPI →
Also registered at 18300 US Highway 18
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Marshall Roy Koon in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license PA20578Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
94% fewer Medicare Part D claims than the average medical physician assistant in 2024
69 Medicare Part D claims for 44 beneficiaries, against an average of 1,148 among the 23,801 providers of this specialty who prescribed in Part D.
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The practice group's MIPS final score for 2023 (Medicare payment program): 94.6 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Marshall Roy Koon among 3,376 medical physician assistant records in California
Marshall Roy Koon, PA-C is one of 3,376 medical physician assistant records with a practice address in California. 69% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2009, is newer than 38% of them.
- NPI issued2009 · 38% of these records are older, 58% newer
- In a Medicare fileYes · 69% of these records are
- In the CMS Doctors and Clinicians fileNo · 40% of these records are
- Record last updated2009 · 54% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363AM0700X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
16 medical physician assistant records list a practice address in Apple Valley
They are 16 of the 1,518 NPPES records with a practice address in Apple Valley, and 3,376 medical physician assistant records in California.
All 3,376 in California → Every provider in Apple Valley → Medical Physician Assistant nationwide →
The 8 medical physician assistant records with the nearest ZIP codes
- Nuha Alomari, PA-CApple Valley, CA 923071497582209
- Tait Christensen, PA-CApple Valley, CA 923071861775611
- Michael Erskine, PA-CApple Valley, CA 923071053369009
- Elias Frangos, PA-CApple Valley, CA 923071235697376
- Isabel GalvezApple Valley, CA 923071932945847
- Gabrielle GonzalezApple Valley, CA 923071942601430
- Bruce Jackson, P.A.Apple Valley, CA 923071124072087
- John Nicolaisen, PAApple Valley, CA 923071548666738
Common questions
What is Marshall Roy Koon, PA-C's NPI number?
Marshall Roy Koon, PA-C's National Provider Identifier (NPI) is 1982939302, issued on Oct 4, 2009. An NPI identifies a provider in billing; it is not a license.
Where is Marshall Roy Koon, PA-C located?
The NPPES record lists a practice address at 18300 US Highway 18, Apple Valley, CA, 92307. Phone: (760) 242-2311. Providers update this record themselves, so call before visiting.
How can I verify Marshall Roy Koon, PA-C's license?
NPPES lists California license number PA20578, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Marshall Roy Koon, PA-C prescribe under Medicare Part D?
In 2024, Marshall Roy Koon, PA-C had 69 Medicare Part D claims for 44 beneficiaries; the average among medical physician assistant prescribers was 1,148. Part D covers Medicare prescriptions only.
What is Marshall Roy Koon, PA-C's MIPS final score?
The 2023 MIPS final score is 94.6 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.