Julia Olson Farmer, MD
Internal Medicine Physician · Vista, CA
Julia Olson Farmer, MD is an internal medicine physician with a practice address in Vista, California, and NPI 1508959347, issued on Oct 2, 2006. Check the license (California C171929, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Julia Olson Farmer
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License numbers
- C171929 CA
43102 CO
Self-reported in NPPES; status is on the state search - Practice location
- 105 Durian St Ste B, Vista, CA 92083
- Phone
- (760) 631-5000
- Enumerated
- Oct 2, 2006
- Record last updated
- Feb 26, 2025
- Fax
- (760) 414-3892
- Medicaid ID
- 1508959347 CO
- Medicare enrollment
- Enrolled (PECOS I20250917002139); may accept Medicare assignment
- Medical or professional school
- University Of California, Davis School Of Medicine, 2002
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 105 Durian St Ste B
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Max Chen, M.D.Internal Medicine Physician1285750356
Verify Julia Olson Farmer in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license C171929Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
42% more Medicare Part D claims than the average internal medicine physician in 2024
4,517 Medicare Part D claims for 269 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 16% of claims. 45 claims were for opioids.
Most prescribed
- Atorvastatin Calcium430 claims
- Amlodipine Besylate251 claims
- Metformin Hcl191 claims
- Levothyroxine Sodium180 claims
- Gabapentin174 claims
- Lisinopril154 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: $161.84
3 payments; by number, the most common kind was food and beverage; the largest payer was Abbott Laboratories. The 50,334 providers of this specialty with any payment received $1,303.06 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.
Julia Olson Farmer among 17,696 internal medicine physician records in California
Julia Olson Farmer, 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 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
- Graduated2002 · median 2004 among the 11,065 with a school on file
- Record last updated2025 · 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).
43 internal medicine physician records list a practice address in Vista
They are 43 of the 2,017 NPPES records with a practice address in Vista, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Vista → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Emad Abu-Khieran, MDVista, CA 920831558314237
- Kristin Bell, M.D.Vista, CA 920831154335891
- Sanjana Chaturvedi, MDVista, CA 920831881630457
- Farzaneh Hassani, MDVista, CA 920831942204979
- John Lafata, MDVista, CA 920831285662403
- Kiran Mahl-Sansone, M.D., INC.Vista, CA 920831245276815
- Mark O'Brien, D.O.Vista, CA 920831497744247
- Gerald Ondash, MDVista, CA 920831730102153
Common questions
What is Julia Olson Farmer, MD's NPI number?
Julia Olson Farmer, MD's National Provider Identifier (NPI) is 1508959347, issued on Oct 2, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Julia Olson Farmer, MD located?
The NPPES record lists a practice address at 105 Durian St Ste B, Vista, CA, 92083. Phone: (760) 631-5000. Providers update this record themselves, so call before visiting.
How can I verify Julia Olson Farmer, MD's license?
NPPES lists California license number C171929, 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 Julia Olson Farmer, MD prescribe under Medicare Part D?
In 2024, Julia Olson Farmer, MD had 4,517 Medicare Part D claims for 269 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.