Dr. Gary L. Kobayashi, MD
- Medicare services, 2024
- 546
- Medicare patients, 2024
- 185
- Part D claims, 2024
- 6,791
- Industry payments
- $1,281
- Affiliated sites
- 3
- Practice address
- 145 Thunder Dr, Vista, CA 92083
- Practice phone
- Call (562) 594-6599
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Optumcare Medical Group
Primary care practice · Vista, California
Find Dr. Kobayashi's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. Gary L. Kobayashi is an internist in Vista, California
Dr. Kobayashi practices at Optumcare Medical Group in Vista, California.
Dr. Kobayashi's NPI, 1245303353, was assigned on November 16, 2006. Dr. Kobayashi graduated from University of California, Geffen School of Medicine in 1985. Dr. Kobayashi holds California license G58496.
- NPI
- 1245303353NPI Registry (opens in a new tab)
- NPI enumeration date
- November 16, 2006
- NPI status
- Active
- Practice phone
- (562) 594-6599
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 67
- Medical school graduation
- 1985
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Dr. Gary L. Kobayashi practices at Optumcare Medical Group in Vista, California
Dr. Kobayashi's primary practice is Optumcare Medical Group, at 145 Thunder Dr, Vista, CA 92083. The practice phone is (562) 594-6599.
- Optumcare Medical Group145 Thunder Dr, Vista, CA 92083Phone(562) 594-6599
Source: Dmand AI Affiliation Data
Dr. Gary L. Kobayashi is affiliated with 3 sites of care and 3 medical groups
Dr. Kobayashi's primary practice is Optumcare Medical Group in Vista, California. The medical group on file is OptumCare Medical Group. Dmand AI also links Dr. Kobayashi to 2 more group practices and clinics and 2 medical groups, each named with a free account.
Source: Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Gary L. Kobayashi's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Kobayashi practices, 3 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Optumcare Medical Group | Available with a free account |
| +2 more sites and 2 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Gary L. Kobayashi is one of 16,751 internists in California
Internal medicine is Dr. Kobayashi's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Kobayashi is licensed in California.
Specialties and state licenses
- Internal medicine, CaliforniaPrimary
Internists near Dr. Kobayashi
Counts of internists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Gary L. Kobayashi billed Medicare for 546 services in 2024
CMS data shows 546 Medicare services from Dr. Kobayashi across 11 procedure codes in 2024, for 185 Medicare patients. Medicare paid $47,418 for them. Every service was in an office.
Dr. Kobayashi's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 1262024: 376198%
- Other services
- 2023: 122024: 99725%
- Tests and treatments
- 2023: 122024: 71492%
Dr. Kobayashi compared with the California median for internists, 2024
- Dr. Kobayashi
- California median
- Medicare services
- 546vs 36151% above
- Medicare patients
- 185vs 15123% above
- Part D claims
- 6,192vs 42114.7 times
Medians across 15,815 internists in California with Dmand AI profiles that report each measure.
Dr. Kobayashi's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Gary L. Kobayashi treated 185 Medicare patients in 2024, average age 77
CMS counts 185 Medicare patients who saw Dr. Kobayashi in 2024. The largest group is 75 to 84, with 77 patients. 75% of them have high blood pressure, and 67% have high cholesterol. Their average risk score is 1.05, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Dr. Kobayashi's median patient age at 71, with 44% women.
Dr. Kobayashi's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Dr. Kobayashi's Medicare patients by sex, 2024
- Women8546%
- Men10054%
Chronic conditions among Dr. Kobayashi's Medicare patients, 2024
- High blood pressure75%
- High cholesterol67%
- Arthritis34%
- Diabetes29%
- Chronic kidney disease23%
- Cancer21%
- Ischemic heart disease21%
- Atrial fibrillation19%
Share of Medicare patients with each condition. A patient can have several.
Dr. Kobayashi's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 71
Patient panel by sex, all payers
- Women44%
- Men55%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Gary L. Kobayashi wrote 6,791 Medicare Part D claims in 2024
In 2024, Dr. Kobayashi wrote 6,791 Medicare Part D claims for 553 patients. 88% of them were for generic drugs. CMS names the drug for 6,192 of them, across 121 drugs with 11 or more claims each, at $643,143 in total drug cost. In 2023, CMS named 6,661 claims across 127 drugs.
Dr. Kobayashi's Part D claims by kind of drug, 2024
- Generic5,970 claims88%
- Brand-name778 claims11%
- Other43 claims1%
Dr. Kobayashi's most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Kobayashi's Part D claims, 2024
- Opioids4%270 of 6,791 claims
- Antibiotics2%123 of 6,791 claims
- Antipsychotics, patients 65 and over0%20 of 6,791 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 6,6612024: 6,1927%
Drugs named by CMS: 121 in 2024, 127 in 2023.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
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Dr. Gary L. Kobayashi received $1,281 in industry payments from 2016 to 2019
CMS Open Payments shows 80 general payments to Dr. Kobayashi from 15 drug and device companies from 2016 to 2019. Food and beverage make up the largest share, 95% of the total. Novo Nordisk Inc paid the most, $409.
General payments to Dr. Kobayashi by program year, 2016 to 2019
General payments to Dr. Kobayashi by kind, 2016 to 2019
- Food and beverage$1,21795%
- Education$655%
Companies that paid Dr. Kobayashi the most, 2016 to 2019
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Gary L. Kobayashi graduated from University of California, Geffen School of Medicine
Dr. Kobayashi graduated from University of California, Geffen School of Medicine in 1985.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Gary L. Kobayashi's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Gary L. Kobayashi
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Gary L. Kobayashi's NPI number?
Dr. Gary L. Kobayashi's NPI number is 1245303353. It was assigned on November 16, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Gary L. Kobayashi?
Dr. Gary L. Kobayashi is an internist in Vista, California. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Gary L. Kobayashi practice?
Dr. Kobayashi practices at 145 Thunder Dr, Vista, CA 92083. Dr. Kobayashi's primary practice is Optumcare Medical Group in Vista, California. Dmand AI also links Dr. Kobayashi to 2 group practices and clinics and 2 medical groups.
What is Dr. Gary L. Kobayashi's office phone number?
The practice phone on file for Dr. Kobayashi is (562) 594-6599.
What is Dr. Gary L. Kobayashi's medical license number?
Dr. Kobayashi holds California license G58496.
What medical group is Dr. Gary L. Kobayashi part of?
Dr. Kobayashi is linked to OptumCare Medical Group. Dmand AI links Dr. Kobayashi to 2 more medical groups.
Does Dr. Gary L. Kobayashi accept Medicare?
Yes. CMS data shows Dr. Kobayashi billed Medicare for 546 services in 2024.
How many Medicare patients does Dr. Gary L. Kobayashi see?
CMS counts 185 Medicare patients who saw Dr. Kobayashi in 2024, with an average age of 77.
What services does Dr. Gary L. Kobayashi bill to Medicare?
In 2024, Dr. Kobayashi's most billed Medicare services were office visit, established patient (99214), office visit, established patient (99213) and medicare service (G0008).
Where did Dr. Gary L. Kobayashi go to medical school?
Dr. Kobayashi graduated from University of California, Geffen School of Medicine in 1985.
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What drugs does Dr. Gary L. Kobayashi prescribe most?
In 2024 Medicare Part D data, Dr. Kobayashi's most prescribed drugs by claims were Atorvastatin Calcium, Amlodipine Besylate and Lisinopril.
Has Dr. Gary L. Kobayashi received payments from drug or device companies?
CMS Open Payments shows $1,281 in general payments to Dr. Kobayashi from 15 companies from 2016 to 2019. The largest total came from Novo Nordisk Inc.
How long has Dr. Gary L. Kobayashi been practicing?
Dr. Kobayashi graduated from medical school in 1985, 41 years ago.
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