John Spencer Mays, MD
Internal Medicine Physician · Saint Louis, MO
John Spencer Mays, MD is an internal medicine physician with a practice address in Saint Louis, Missouri, and NPI 1083108062, issued on Jun 21, 2018. Check the license (Missouri 2020001817, as entered in NPPES) on the Missouri Board of Registration for the Healing Arts; the Medicare figures below come from public CMS files.
- Name
- John Spencer Mays
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 2020001817 MO
Self-reported in NPPES; status is on the state search - Practice location
- 969 N Mason RD Ste 110, Saint Louis, MO 63141
- Phone
- (314) 996-3434
- Enumerated
- Jun 21, 2018
- Record last updated
- Mar 22, 2023
- Medicare enrollment
- Enrolled (PECOS I20210714000243); accepts Medicare assignment
- Medical or professional school
- University Of Tennessee, Hsc, College Of Medicine, 2018
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,604 in Missouri → Look up another NPI →
Also registered at 969 N Mason RD Ste 110
A shared address usually means a shared clinic or building; it does not show who employs whom.
- David Brown, M.D.Internal Medicine Physician1861433195
- Christopher Chappell, DOFamily Medicine Physician1649651910
- Paul L'Ecuyer, MDInternal Medicine Physician1427161298
- Katherine Martin-Bredahl, FNPNurse Practitioner1427388776
- Eileen McKeon, ANPNurse Practitioner1477768877
- Caitlynn Murphy, APRN, FNP-CNurse Practitioner1942904156
Verify John Spencer Mays 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 2020001817Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
4.7 times the Medicare Part D claims of the average internal medicine physician in 2024
14,827 Medicare Part D claims for 1,354 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims. 606 claims were for opioids.
Most prescribed
- Atorvastatin Calcium749 claims
- Rosuvastatin Calcium632 claims
- Levothyroxine Sodium596 claims
- Amlodipine Besylate521 claims
- Lisinopril442 claims
- Losartan Potassium429 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.
Industry payments in 2024: $1,491.34
83 payments; by number, the most common kind was food and beverage; the largest payer was Abbvie Inc. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through 4 group practices
- Arnold Physical Therapy And Sports Medicine LLCSaint Louis, MO
- Elite Physical Therapy OF Creve Coeur LLCCreve Coeur, MO
- Physical Therapy Spine And Sports Medicine LLCBallwin, MO
- Physician Groups LCSaint Louis, MO
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
John Spencer Mays among 2,604 internal medicine physician records in Missouri
John Spencer Mays, MD 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 2018, is newer than 69% of them.
- NPI issued2018 · 69% of these records are older, 28% newer
- In a Medicare fileYes · 77% of these records are
- In the CMS Doctors and Clinicians fileYes · 55% of these records are
- Graduated2018 · median 2006 among the 1,443 with a school on file
- Record last updated2023 · 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
- Daniel Bauer, MDSaint Louis, MO 631411144222506
- Michele Bellamy, MDCreve Coeur, MO 631411134194863
- Shobha Dixit, MDSaint Louis, MO 631411902871650
- Carolyn Koenig, MDSaint Louis, MO 631411063488278
- Bernard McGuire, M.D.Saint Louis, MO 631411942274030
- Angela Miller, M.D.Saint Louis, MO 631411184605883
- C Molden, MDSaint Louis, MO 631411720086747
- Margaret Murphy, M.D.Saint Louis, MO 631411043285745
Common questions
What is John Spencer Mays, MD's NPI number?
John Spencer Mays, MD's National Provider Identifier (NPI) is 1083108062, issued on Jun 21, 2018. An NPI identifies a provider in billing; it is not a license.
Where is John Spencer Mays, MD located?
The NPPES record lists a practice address at 969 N Mason RD Ste 110, Saint Louis, MO, 63141. Phone: (314) 996-3434. Providers update this record themselves, so call before visiting.
How can I verify John Spencer Mays, MD's license?
NPPES lists Missouri license number 2020001817, 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 John Spencer Mays, MD prescribe under Medicare Part D?
In 2024, John Spencer Mays, MD had 14,827 Medicare Part D claims for 1,354 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
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.