Nathaniel Welsh Best, PA-C
Physician Assistant · Saint Charles, MO
Nathaniel Welsh Best, PA-C is a physician assistant with a practice address in Saint Charles, Missouri, and NPI 1467928408, issued on Oct 17, 2018. Check the license (Missouri 2020030531, as entered in NPPES) with the Missouri board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Nathaniel Welsh Best
- Credential
- PA-C
- Primary taxonomy
- Physician Assistant 363A00000X
- License numbers
- 2020030531 MO
126823 IA
085.006912 IL
Self-reported in NPPES; status is on the state search - Practice location
- 300 1St Capitol Dr, Saint Charles, MO 63301
- Phone
- (636) 947-5000
- Enumerated
- Oct 17, 2018
- Record last updated
- Sep 10, 2024
- Medicare enrollment
- Enrolled (PECOS I20211020001867); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest physician assistant records → All 1,790 in Missouri → Look up another NPI →
Also registered at 300 1St Capitol Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Ellen Atwood, PA-CPhysician Assistant1487104303
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Verify Nathaniel Welsh Best in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich Missouri board licenses this profession
Search for license 2020030531Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
80% fewer Medicare Part D claims than the average physician assistant in 2024
164 Medicare Part D claims for 125 beneficiaries, against an average of 830 among the 101,058 providers of this specialty who prescribed in Part D. 22 claims were for opioids.
Most prescribed
- Hydrocodone-Acetaminophen21 claims
- Cefadroxil16 claims
- Ondansetron Odt11 claims
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): 89.6 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).
Bills Medicare through one group practice
- Cep America LLCFenton, MO
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Nathaniel Welsh Best among 1,790 physician assistant records in Missouri
Nathaniel Welsh Best, PA-C is one of 1,790 physician assistant records with a practice address in Missouri. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2018, is newer than 46% of them.
- NPI issued2018 · 46% of these records are older, 50% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Graduated2018 · median 2019 among the 1,250 with a school on file
- Record last updated2024 · 32% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363A00000X and a Missouri practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
22 physician assistant records list a practice address in Saint Charles
They are 22 of the 1,547 NPPES records with a practice address in Saint Charles, and 1,790 physician assistant records in Missouri.
All 1,790 in Missouri → Every provider in Saint Charles → Physician Assistant nationwide →
The 8 physician assistant records with the nearest ZIP codes
- Ellen Atwood, PA-CSaint Charles, MO 633011487104303
- Ray Bartlett, P.A.Saint Charles, MO 633011194738260
- Kathleen Christlieb, PASaint Charles, MO 633011013112176
- Bridget Franklin, PASaint Charles, MO 633011568996213
- Jennifer Herndon, P.ASaint Charles, MO 633011629217690
- Mark Johnson, PA-C MT ASCPSaint Charles, MO 633011568453132
- Rachel Kitzmann, PA-CSaint Charles, MO 633011588448583
- Kathleen Nikodym, PASaint Charles, MO 633011235210162
Common questions
What is Nathaniel Welsh Best, PA-C's NPI number?
Nathaniel Welsh Best, PA-C's National Provider Identifier (NPI) is 1467928408, issued on Oct 17, 2018. An NPI identifies a provider in billing; it is not a license.
Where is Nathaniel Welsh Best, PA-C located?
The NPPES record lists a practice address at 300 1St Capitol Dr, Saint Charles, MO, 63301. Phone: (636) 947-5000. Providers update this record themselves, so call before visiting.
How can I verify Nathaniel Welsh Best, PA-C's license?
NPPES lists Missouri license number 2020030531, as entered by the provider. Search the Missouri board that licenses this profession; the NPPES record confirms identity only.
How much does Nathaniel Welsh Best, PA-C prescribe under Medicare Part D?
In 2024, Nathaniel Welsh Best, PA-C had 164 Medicare Part D claims for 125 beneficiaries; the average among physician assistant prescribers was 830. Part D covers Medicare prescriptions only.
What is Nathaniel Welsh Best, PA-C's MIPS final score?
The 2023 MIPS final score is 89.6 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.