John D. Marcum, MD
Allergy & Immunology Physician · St Clair, MO
John D. Marcum, MD is an allergy & immunology physician with a practice address in St Clair, Missouri, and NPI 1720113053, issued on Feb 23, 2007. Check the license (Missouri R3G15, 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 D. Marcum
- Credential
- MD
- Primary taxonomy
- Allergy & Immunology Physician 207K00000X
- License numbers
- R3G15 MO
G38741 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1020 St Clair Plaza, St Clair, MO 63077
- Phone
- (636) 629-6030
- Enumerated
- Feb 23, 2007
- Record last updated
- Jun 26, 2014 (not updated in 12 years: call before relying on the address or phone)
- Fax
- (636) 629-6030
- Entity
- Type 1 · individual
8 nearest allergy & immunology physician records → All 36 in Missouri → Look up another NPI →
Verify John D. Marcum 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 R3G15Check 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 allergy & immunology physician in 2024
15 Medicare Part D claims, against an average of 741 among the 2,899 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.
John D. Marcum among 36 allergy & immunology physician records in Missouri
John D. Marcum, MD is one of 36 allergy & immunology physician records with a practice address in Missouri. 78% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 42% of them.
- NPI issued2007 · 42% of these records are older, 31% newer
- In a Medicare fileYes · 78% of these records are
- In the CMS Doctors and Clinicians fileNo · 64% of these records are
- Record last updated2014 · 56% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207K00000X and a Missouri practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Allergy & Immunology Physician providers in Missouri
There are 36 allergy & immunology physician records in Missouri.
All 36 in Missouri → Allergy & Immunology Physician nationwide →
The 8 allergy & immunology physician records with the nearest ZIP codes
- Ravneet Donegan, M.D.Saint Louis, MO 631041497041735
- Ashley Emmert, MDSaint Louis, MO 631091699948745
- Khaled Abdel-Hamid, MDSaint Louis, MO 631101679591572
- Ritu Gupta, M.D.St Louis, MO 631101083810808
- Jeremy Katcher, MDSaint Louis, MO 631101124235239
- Zhen Ren, MDSaint Louis, MO 631101982026696
- Amit Shah, M.D.Festus, MO 630281134246770
- Michael Borts, M.D.Saint Louis, MO 631271912991753
Common questions
What is John D. Marcum, MD's NPI number?
John D. Marcum, MD's National Provider Identifier (NPI) is 1720113053, issued on Feb 23, 2007. An NPI identifies a provider in billing; it is not a license.
Where is John D. Marcum, MD located?
The NPPES record lists a practice address at 1020 St Clair Plaza, St Clair, MO, 63077. Phone: (636) 629-6030. Providers update this record themselves, so call before visiting.
How can I verify John D. Marcum, MD's license?
NPPES lists Missouri license number R3G15, 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 D. Marcum, MD prescribe under Medicare Part D?
In 2024, John D. Marcum, MD had 15 Medicare Part D claims; the average among allergy & immunology physician prescribers was 741. 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.