Diana Hess, MD
Internal Medicine Physician · Castro Valley, CA
Diana Hess, MD is an internal medicine physician with a practice address in Castro Valley, California, and NPI 1295296275, issued on Mar 30, 2019. Check the license (California 178427, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Diana Hess
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 178427 CA
Self-reported in NPPES; status is on the state search - Practice location
- 20101 Lake Chabot RD FL 3, Castro Valley, CA 94546
- Phone
- (510) 886-3400
- Enumerated
- Mar 30, 2019
- Record last updated
- Oct 30, 2024
- Medicare enrollment
- Enrolled (PECOS I20220603002563); accepts Medicare assignment
- Medical or professional school
- Univ Of Central Florida, College Of Medicine, 2019
- 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 20101 Lake Chabot RD FL 3
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Ahlam Algazzali, PHYSICIAN ASSISTANTPhysician Assistant1083210017
- Ahmad Ayoubi, M.D., M.SFamily Medicine Physician1992926075
- Naomi Bitow, MDFamily Medicine Physician1184038895
- Kristin Brew, MDOtolaryngology Physician1669568655
- Carol Choy, RN, CDEDiabetes Educator Registered Nurse1578076600
- Beth Ehrlich, AUDAudiologist1669473195
Verify Diana Hess in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license 178427Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
78% fewer Medicare Part D claims than the average internal medicine physician in 2024
683 Medicare Part D claims for 130 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 13 claims were for opioids.
Most prescribed
- Atorvastatin Calcium48 claims
- Losartan Potassium37 claims
- Rosuvastatin Calcium37 claims
- Amlodipine Besylate29 claims
- Levothyroxine Sodium29 claims
- Metformin Hcl26 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
- Sutter Bay Medical FoundationCastro Valley, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Diana Hess among 17,696 internal medicine physician records in California
Diana Hess, MD 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 2019, is newer than 86% of them.
- NPI issued2019 · 86% of these records are older, 11% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2019 · median 2004 among the 11,065 with a school on file
- Record last updated2024 · 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).
24 internal medicine physician records list a practice address in Castro Valley
They are 24 of the 999 NPPES records with a practice address in Castro Valley, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Castro Valley → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Nabil Abudayeh, MDCastro Valley, CA 945461699724484
- Monica Bhargava, MDCastro Valley, CA 945461619900347
- Wing Chin, M.D.Castro Valley, CA 945461124052576
- Richard Ho, M. D.Castro Valley, CA 945461548283005
- Kathryn Hodge, MDCastro Valley, CA 945461194741256
- Nidhi Johri, M.DCastro Valley, CA 945461285811489
- Samir Kadada, M.D.Castro Valley, CA 945461952315202
- Donald Knotts, MEDICAL DOCTORCastro Valley, CA 945461790858611
Common questions
What is Diana Hess, MD's NPI number?
Diana Hess, MD's National Provider Identifier (NPI) is 1295296275, issued on Mar 30, 2019. An NPI identifies a provider in billing; it is not a license.
Where is Diana Hess, MD located?
The NPPES record lists a practice address at 20101 Lake Chabot RD FL 3, Castro Valley, CA, 94546. Phone: (510) 886-3400. Providers update this record themselves, so call before visiting.
How can I verify Diana Hess, MD's license?
NPPES lists California license number 178427, 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 Diana Hess, MD prescribe under Medicare Part D?
In 2024, Diana Hess, MD had 683 Medicare Part D claims for 130 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.