William Stephen Knapp, D.O.
Geriatric Medicine (Family Medicine) Physician · Florissant, MO
William Stephen Knapp, D.O. is a geriatric medicine (family medicine) physician with a practice address in Florissant, Missouri, and NPI 1023099140, issued on Nov 7, 2005. Check the license (Missouri R8885, as entered in NPPES) on the Missouri Board of Registration for the Healing Arts; the Medicare figures below come from public CMS files.
- Name
- William Stephen Knapp
- Credential
- D.O.
- Primary taxonomy
- Geriatric Medicine (Family Medicine) Physician 207QG0300X
- License number
- R8885 MO
Self-reported in NPPES; status is on the state search - Practice location
- 2137 Charbonier RD Ste B, Florissant, MO 63031
- Phone
- (314) 831-0181
- Enumerated
- Nov 7, 2005
- Record last updated
- Feb 8, 2019 (not updated in 7 years: call before relying on the address or phone)
- Fax
- (314) 851-4471
- Medicaid ID
- 241162304 MO
- Medicare enrollment
- Enrolled (PECOS I20071204000712); accepts Medicare assignment
- Medical or professional school
- At Still University Of Health Sciences, College Of Osteo Med, Kirksville, 1978
- Entity
- Type 1 · individual
8 nearest geriatric medicine (family medicine) physician records → All 32 in Missouri → Look up another NPI →
Also registered at 2137 Charbonier RD Ste B
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Julia Freund, PA-CPhysician Assistant1780313288
- Rachel Sappington, RN, FNP-BCFamily Nurse Practitioner1013436492
Verify William Stephen Knapp 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 R8885Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
3.3 times the Medicare Part D claims of the average geriatric medicine (family medicine) physician in 2024
17,182 Medicare Part D claims for 875 beneficiaries, against an average of 5,222 among the 1,271 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 905 claims were for opioids.
Most prescribed
- Rosuvastatin Calcium744 claims
- Atorvastatin Calcium656 claims
- Amlodipine Besylate509 claims
- Levothyroxine Sodium502 claims
- Metoprolol Succinate487 claims
- Lisinopril478 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: $832.41
33 payments; by number, the most common kind was food and beverage; the largest payer was AstraZeneca Pharmaceuticals LP. The 460 providers of this specialty with any payment received $1,218.49 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 one group practice
- American Multispecialty Group IncFlorissant, MO
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William Stephen Knapp among 32 geriatric medicine (family medicine) physician records in Missouri
William Stephen Knapp, D.O. is one of 32 geriatric medicine (family medicine) physician records with a practice address in Missouri. 72% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 78% newer
- In a Medicare fileYes · 72% of these records are
- In the CMS Doctors and Clinicians fileYes · 47% of these records are
- Graduated1978 · median 1985 among the 15 with a school on file
- Record last updated2019 · 53% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207QG0300X and a Missouri practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Geriatric Medicine (Family Medicine) Physician providers in Missouri
There are 32 geriatric medicine (family medicine) physician records in Missouri.
All 32 in Missouri → Every provider in Florissant → Geriatric Medicine (Family Medicine) Physician nationwide →
The 8 geriatric medicine (family medicine) physician records with the nearest ZIP codes
- James Ellegood, M.D.De Soto, MO 630201760479372
- Patricia Inman, MDChesterfield, MO 630171265546923
- Mehwish Siddiqui, M.D.Saint Louis, MO 631041073177051
- Richard Schamp, M.D.Saint Louis, MO 631051447361977
- Anupam Agarwal, MDSaint Louis, MO 631251316996580
- Ming Hao, M.D.Saint Louis, MO 631271861607640
- Homer Brooks, M.D.Poplar Bluff, MO 639011154397537
- Jafar Ohiokpehai, MDGrandview, MO 640301346850559
Common questions
What is William Stephen Knapp, D.O.'s NPI number?
William Stephen Knapp, D.O.'s National Provider Identifier (NPI) is 1023099140, issued on Nov 7, 2005. An NPI identifies a provider in billing; it is not a license.
Where is William Stephen Knapp, D.O. located?
The NPPES record lists a practice address at 2137 Charbonier RD Ste B, Florissant, MO, 63031. Phone: (314) 831-0181. Providers update this record themselves, so call before visiting.
How can I verify William Stephen Knapp, D.O.'s license?
NPPES lists Missouri license number R8885, 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 William Stephen Knapp, D.O. prescribe under Medicare Part D?
In 2024, William Stephen Knapp, D.O. had 17,182 Medicare Part D claims for 875 beneficiaries; the average among geriatric medicine (family medicine) physician prescribers was 5,222. 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.