Matthew Guest, M.D
Internal Medicine Physician · Escondido, CA
Matthew Guest, M.D is an internal medicine physician with a practice address in Escondido, California, and NPI 1023038601, issued on Jul 19, 2006. Check the license (California A91381, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Matthew Guest
- Credential
- M.D
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A91381 CA
Self-reported in NPPES; status is on the state search - Practice location
- 460 N Elm St, Escondido, CA 92025
- Phone
- (760) 737-2000
- Enumerated
- Jul 19, 2006
- Record last updated
- Nov 29, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (760) 737-2039
- Medicare enrollment
- Enrolled (PECOS I20060831000533); accepts Medicare assignment
- Medical or professional school
- State University Of New York At Buffalo School Of Medicine, 2003
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 460 N Elm St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Anmar AlhaddadPhysician Assistant1780573634
- Lucy Artman, PA-CPhysician Assistant1962213116
- Michael Avila, M.D.Family Medicine Physician1962936450
- Ruth Bravo, NPNurse Practitioner1013938224
- Betty Brown, NPNurse Practitioner1659394716
- Samantha Chambers, NPFamily Nurse Practitioner1851768667
Verify Matthew Guest in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A91381Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
3.0 times the Medicare Part D claims of the average internal medicine physician in 2024
9,446 Medicare Part D claims for 1,090 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 461 claims were for opioids.
Most prescribed
- Atorvastatin Calcium732 claims
- Amlodipine Besylate382 claims
- Losartan Potassium360 claims
- Levothyroxine Sodium315 claims
- Omeprazole307 claims
- Metformin Hcl Er288 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
- Southern California Permanente Medical GroupLa Mesa, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Matthew Guest among 17,696 internal medicine physician records in California
Matthew Guest, M.D is one of 17,696 internal medicine physician records with a practice address in California. 79% 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 5% of them.
- NPI issued2006 · 5% of these records are older, 56% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2003 · median 2004 among the 11,065 with a school on file
- Record last updated2021 · 61% 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 California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
44 internal medicine physician records list a practice address in Escondido
They are 44 of the 3,509 NPPES records with a practice address in Escondido, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Escondido → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Rachel Bacon, M.DEscondido, CA 920251215963905
- Margaret Chen, M.DEscondido, CA 920251659305084
- Larry Chiang, MDEscandido, CA 920251912952524
- Mark Haberman, M.D.Escondido, CA 920251497780563
- Karin Kordas, M.D.Escondido, CA 920251043236292
- Lara Le, MDEscondido, CA 920251043239841
- Emmet Lee, M.D.Escondido, CA 920251558326801
- Richard Mallo, MDEscondido, CA 920251588699490
Common questions
What is Matthew Guest, M.D's NPI number?
Matthew Guest, M.D's National Provider Identifier (NPI) is 1023038601, issued on Jul 19, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Matthew Guest, M.D located?
The NPPES record lists a practice address at 460 N Elm St, Escondido, CA, 92025. Phone: (760) 737-2000. Providers update this record themselves, so call before visiting.
How can I verify Matthew Guest, M.D's license?
NPPES lists California license number A91381, as entered by the provider. 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 Matthew Guest, M.D prescribe under Medicare Part D?
In 2024, Matthew Guest, M.D had 9,446 Medicare Part D claims for 1,090 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.