Guy William Felder, M.D.
Internal Medicine Physician · Saint Louis, MO
Guy William Felder, M.D. is an internal medicine physician with a practice address in Saint Louis, Missouri, and NPI 1427159714, issued on Sep 26, 2006. Check the license (Missouri R8J13, as entered in NPPES) on the Missouri Board of Registration for the Healing Arts; the Medicare figures below come from public CMS files.
- Name
- Guy William Felder
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- R8J13 MO
Self-reported in NPPES; status is on the state search - Practice location
- 5640C Telegraph RD, Saint Louis, MO 63129
- Phone
- (314) 293-4413
- Enumerated
- Sep 26, 2006
- Record last updated
- Nov 13, 2025
- Medicare enrollment
- Enrolled (PECOS I20080417000366); accepts Medicare assignment
- Medical or professional school
- Saint Louis University School Of Medicine, 1988
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,604 in Missouri → Look up another NPI →
Verify Guy William Felder in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMissouri Board of Registration for the Healing Arts
Search for license R8J13Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% fewer Medicare Part D claims than the average internal medicine physician in 2024
74 Medicare Part D claims for 45 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 24 claims were for opioids.
Most prescribed
- Hydrocodone-Acetaminophen16 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 MIPS final score for 2023 (Medicare payment program): 89.2 of 100
The Merit-based Incentive Payment System score is reported for this clinician. 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; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Mercy East Ambulatory Services LLCSaint Louis, MO
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Guy William Felder among 2,604 internal medicine physician records in Missouri
Guy William Felder, M.D. is one of 2,604 internal medicine physician records with a practice address in Missouri. 77% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 8% of them.
- NPI issued2006 · 8% of these records are older, 59% newer
- In a Medicare fileYes · 77% of these records are
- In the CMS Doctors and Clinicians fileYes · 55% of these records are
- Graduated1988 · median 2006 among the 1,443 with a school on file
- Record last updated2025 · 48% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Missouri practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
941 internal medicine physician records list a practice address in Saint Louis
They are 941 of the 27,605 NPPES records with a practice address in Saint Louis, and 2,604 internal medicine physician records in Missouri.
All 2,604 in Missouri → Every provider in Saint Louis → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Kamal Demetry, M.D.Saint Louis, MO 631291174548549
- Victoria Ojascastro, M.D.Saint Louis, MO 631291285742858
- Soha Afzal, DOSaint Louis, MO 631281023696507
- Vaghdevi Bagam, M.D.Saint Louis, MO 631281609449388
- Sidra Danish, MDSaint Louis, MO 631281841934650
- Muhammed Durmus, MDSaint Louis, MO 631281972274231
- Dina ElsayedSaint Louis, MO 631281669059895
- Stephanie Hammer, MDSaint Louis, MO 631301023025780
Common questions
What is Guy William Felder, M.D.'s NPI number?
Guy William Felder, M.D.'s National Provider Identifier (NPI) is 1427159714, issued on Sep 26, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Guy William Felder, M.D. located?
The NPPES record lists a practice address at 5640C Telegraph RD, Saint Louis, MO, 63129. Phone: (314) 293-4413. Providers update this record themselves, so call before visiting.
How can I verify Guy William Felder, M.D.'s license?
NPPES lists Missouri license number R8J13, as entered by the provider. Search the Missouri Board of Registration for the Healing Arts at https://www.fsmb.org/contact-a-state-medical-board/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Guy William Felder, M.D. prescribe under Medicare Part D?
In 2024, Guy William Felder, M.D. had 74 Medicare Part D claims for 45 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Guy William Felder, M.D.'s MIPS final score?
The 2023 MIPS final score is 89.2 of 100. 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.