Timothy Louis Gieseke, M.D.
Internal Medicine Physician · Santa Rosa, CA
Timothy Louis Gieseke, M.D. is an internal medicine physician with a practice address in Santa Rosa, California, and NPI 1992703706, issued on Jul 14, 2005. Check the license (California G34398, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Timothy Louis Gieseke
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- G34398 CA
Self-reported in NPPES; status is on the state search - Practice location
- 3536 Mendocino Ave, Santa Rosa, CA 95403
- Phone
- (707) 546-2180
- Enumerated
- Jul 14, 2005
- Record last updated
- Feb 7, 2012 (not updated in 14 years: call before relying on the address or phone)
- Fax
- (707) 546-2188
- Medicaid ID
- 00G343980 CA
- Medicare enrollment
- Enrolled (PECOS I20060424000225); may accept Medicare assignment
- Medical or professional school
- University Of California, Irvine, California College Of Medicine, 1976
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 3536 Mendocino Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Timothy Louis Gieseke in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G34398Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
68% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,011 Medicare Part D claims for 88 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 24 claims were for opioids.
Most prescribed
- Atorvastatin Calcium62 claims
- Escitalopram Oxalate35 claims
- Metoprolol Succinate34 claims
- Alendronate Sodium29 claims
- Donepezil Hcl24 claims
- Amlodipine Besylate22 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.
Timothy Louis Gieseke among 17,696 internal medicine physician records in California
Timothy Louis Gieseke, 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 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 95% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1976 · median 2004 among the 11,065 with a school on file
- Record last updated2012 · 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).
98 internal medicine physician records list a practice address in Santa Rosa
They are 98 of the 6,884 NPPES records with a practice address in Santa Rosa, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Santa Rosa → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Harry Carr, M.D.Santa Rosa, CA 954031770694044
- William Carroll, M.D.Santa Rosa, CA 954031922005891
- Lawrence Cooper, M.D.Santa Rosa, CA 954031801895602
- Zhen Zhou Feng, M.D.Santa Rosa, CA 954031871600031
- Archana Goyal, M.D.Santa Rosa, CA 954031811084817
- Parul Kohli, M.D.Santa Rosa, CA 954031023098738
- Maya Land, MDSanta Rosa, CA 954031619958154
- Neil Levin, M.D.Santa Rosa, CA 954031285633081
Common questions
What is Timothy Louis Gieseke, M.D.'s NPI number?
Timothy Louis Gieseke, M.D.'s National Provider Identifier (NPI) is 1992703706, issued on Jul 14, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Timothy Louis Gieseke, M.D. located?
The NPPES record lists a practice address at 3536 Mendocino Ave, Santa Rosa, CA, 95403. Phone: (707) 546-2180. Providers update this record themselves, so call before visiting.
How can I verify Timothy Louis Gieseke, M.D.'s license?
NPPES lists California license number G34398, 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 Timothy Louis Gieseke, M.D. prescribe under Medicare Part D?
In 2024, Timothy Louis Gieseke, M.D. had 1,011 Medicare Part D claims for 88 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.