Mark Shaffer, M.D.
Internal Medicine Physician · La Mesa, CA
Mark Shaffer, M.D. is an internal medicine physician with a practice address in La Mesa, California, and NPI 1255436804, issued on Sep 14, 2006. Check the license on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Mark Shaffer
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- Practice location
- 7877 Parkway Dr, La Mesa, CA 91942
- Phone
- (619) 461-3717
- Enumerated
- Sep 14, 2006
- Entity
- Type 1 · individual
Also registered at 7877 Parkway Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Glenn Cook, MDOphthalmology Physician1013078427
- William Davis, M.D.Cardiovascular Disease Physician1316939978
- Martin Nosan, MDInternal Medicine Physician1184748311
- Anthony Tran, D.D.S.General Practice Dentistry1609963974
- Paul Treger, MDOphthalmology Physician1447311899
Verify Mark Shaffer in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of CaliforniaCheck the board
- 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS, AOA, NCCPA, AANPNot checked
86% fewer Medicare Part D claims than the average internal medicine physician in 2024
383 Medicare Part D claims for 72 beneficiaries, against an average of 2,785 among the 127,794 providers of this specialty who prescribed in Part D.
Most prescribed
- Levothyroxine Sodium60 claims
- Tamsulosin Hcl34 claims
- Atorvastatin Calcium27 claims
- Eliquis23 claims
- Donepezil Hcl16 claims
- Pantoprazole Sodium15 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.
68 internal medicine physician records list a La Mesa practice address
They are 68 of the 2,168 NPPES records with a La Mesa practice address, and 20,403 internal medicine physician records in California.
All 68 in La Mesa → All 20,403 in California → Every provider in La Mesa →
Other internal medicine physician records in California
- Jacob Aaron, MDSan Francisco, CA1407202518
- Alistair Aaronson, MDStanford, CA1457628760
- Jose Abad., MDSacramento, CA1144607219
- Donna Abare, MDOakland, CA1386722155
- Marce AbareScotts Valley, CA1457744708
- Samuel Abarte, M.D.Chula Vista, CA1578535498
- Alexander Abary, MDLong Beach, CA1104995919
- Luba Abascal, MDSan Francisco, CA1023180874
- Michael Abate, MDSacramento, CA1548248131
- Wali Abawi, D.O.Joshua Tree, CA1104362268
Common questions
What is Mark Shaffer, M.D.'s NPI number?
Mark Shaffer, M.D.'s National Provider Identifier (NPI) is 1255436804, issued on Sep 14, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Mark Shaffer, M.D. located?
The NPPES record lists a practice address at 7877 Parkway Dr, La Mesa, CA, 91942. Phone: (619) 461-3717. Providers update this record themselves, so call before visiting.
How can I verify Mark Shaffer, M.D.'s license?
Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Mark Shaffer, M.D. prescribe under Medicare Part D?
In 2024, Mark Shaffer, M.D. had 383 Medicare Part D claims for 72 beneficiaries; the average among internal medicine physician prescribers was 2,785. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), loaded Aug 27, 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.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 27, 2026.