NPPES file of Aug 9, 2026

David Alan Janssen, M.D.

Infectious Disease Physician · O Fallon, MO

David Alan Janssen, M.D. is an infectious disease physician with a practice address in O Fallon, Missouri, and NPI 1700995339, issued on Aug 29, 2006. Check the license (Missouri 208810309, as entered in NPPES) on the Missouri Board of Registration for the Healing Arts; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1700995339
Name
David Alan Janssen
Credential
M.D.
Primary taxonomy
Infectious Disease Physician 207RI0200X
License numbers
208810309 MO
103905 MO
036176531 IL
Self-reported in NPPES; status is on the state search
Practice location
20 Progress Point Pkwy Ste 206, O Fallon, MO 63368
Phone
(636) 344-2014
Enumerated
Aug 29, 2006
Record last updated
Oct 21, 2025
Fax
(314) 747-1476
Medicare enrollment
Enrolled (PECOS I20251031003877); accepts Medicare assignment
Medical or professional school
Indiana University School Of Medicine, 1988
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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8 nearest infectious disease physician records → All 212 in Missouri → Look up another NPI →

Also registered at 20 Progress Point Pkwy Ste 206

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Ayooluwatomiwa Adekunle, MDGastroenterology Physician1619593779
  2. Ashley Batten, DOObstetrics & Gynecology Physician1164095311
  3. Eldad Bialecki, M.D.Gastroenterology Physician1003952458
  4. Jolene Borders, WHNP-BCWomen's Health Nurse Practitioner1598065468
  5. Anna BoschertPhysician Assistant1568236578
  6. Sara Busch, AGNP-CNurse Practitioner1669007100

Verify David Alan Janssen in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMissouri Board of Registration for the Healing Arts
    Search for license 208810309    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the Missouri license search

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4% fewer Medicare Part D claims than the average infectious disease physician in 2024

659 Medicare Part D claims for 93 beneficiaries, against an average of 689 among the 7,388 providers of this specialty who prescribed in Part D. Brand-name drugs were 9% of claims.

  1. David Janssen659
  2. Specialty average689

Most prescribed

  1. Cefuroxime96 claims
  2. Ceftriaxone67 claims
  3. Amoxicillin-Clavulanate Potass62 claims
  4. Ertapenem48 claims
  5. Doxycycline Hyclate38 claims
  6. Vancomycin Hcl29 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.

Bills Medicare through one group practice

  1. Fairview Heights Medical Group SCAlton, IL

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

David Alan Janssen among 212 infectious disease physician records in Missouri

David Alan Janssen, M.D. is one of 212 infectious disease physician records with a practice address in Missouri. 83% 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 3% of them.

  • NPI issued2006 · 3% of these records are older, 56% newer
  • In a Medicare fileYes · 83% of these records are
  • In the CMS Doctors and Clinicians fileYes · 70% of these records are
  • Graduated1988 · median 2004 among the 147 with a school on file
  • Record last updated2025 · 40% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RI0200X and a Missouri practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Infectious Disease Physician providers in Missouri

There are 212 infectious disease physician records in Missouri.

All 212 in Missouri → Every provider in O Fallon → Infectious Disease Physician nationwide →

The 8 infectious disease physician records with the nearest ZIP codes

  1. Manokiran Patri, M.D.Saint Charles, MO 633011649204173
  2. Shephali Wulff, D.OSaint Charles, MO 633011174789747
  3. Lee Yong, M.D.Saint Charles, MO 633011952538522
  4. Nicolo Cabrera, MDSaint Louis, MO 631411366858797
  5. Michael Hendrix, MDSaint Louis, MO 631411881076503
  6. Jad Khoury, M.D.Saint Louis, MO 631411144250028
  7. Frederick Kuhlmann, MDSaint Louis, MO 631411417981481
  8. Hamzah Mohd, M.D.,Saint Louis, MO 631411952559320

Common questions

What is David Alan Janssen, M.D.'s NPI number?

David Alan Janssen, M.D.'s National Provider Identifier (NPI) is 1700995339, issued on Aug 29, 2006. An NPI identifies a provider in billing; it is not a license.

Where is David Alan Janssen, M.D. located?

The NPPES record lists a practice address at 20 Progress Point Pkwy Ste 206, O Fallon, MO, 63368. Phone: (636) 344-2014. Providers update this record themselves, so call before visiting.

How can I verify David Alan Janssen, M.D.'s license?

NPPES lists Missouri license number 208810309, 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 David Alan Janssen, M.D. prescribe under Medicare Part D?

In 2024, David Alan Janssen, M.D. had 659 Medicare Part D claims for 93 beneficiaries; the average among infectious disease physician prescribers was 689. 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.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.