Dr. Thomas K. Onyia, MD
- Medicare services, 2024
- 129
- Medicare patients, 2024
- 210
- Hospital affiliations
- 2
- Industry payments
- $256
- Medical group
- 1
- Practice address
- 10800 Magnolia Avenue, Riverside, CA 92505
- Practice phone
- Call (951) 353-2000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Onyia's professional email, personal email and mobile number
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Dr. Thomas K. Onyia is an anesthesiologist in Riverside, California
Dr. Onyia practices at Riverside Medical Center in Riverside, California, part of Kaiser Permanente.
Dr. Onyia's NPI, 1902283443, was assigned on May 5, 2015. Dr. Onyia graduated from University of California, San Diego School of Medicine in 2015. Dr. Onyia holds California license 149440.
- NPI
- 1902283443NPI Registry (opens in a new tab)
- NPI enumeration date
- May 5, 2015
- NPI status
- Active
- Practice phone
- (951) 353-2000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 37
- Medical school graduation
- 2015
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Dr. Thomas K. Onyia practices at Riverside Medical Center in Riverside, California
Dr. Onyia's primary practice is Riverside Medical Center, at 10800 Magnolia Avenue, Riverside, CA 92505 in Riverside County. The practice phone is (951) 353-2000.
- Riverside Medical Center10800 Magnolia Avenue, Riverside, CA 92505 · Riverside CountyPhone(951) 353-2000
Source: Dmand AI Affiliation Data
Dr. Thomas K. Onyia is affiliated with 2 sites of care and 1 medical group
Dr. Onyia's primary practice is Riverside Medical Center in Riverside, California, part of Kaiser Permanente. Dr. Onyia is also affiliated with Hillcrest Medical Center. The medical group on file is Southern California Permanente Medical Group.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Thomas K. Onyia's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Onyia practices, 2 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Riverside Medical Center | Available with a free account |
| +1 more affiliated site | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Thomas K. Onyia is one of 6,593 anesthesiologists in California
Anesthesiology is Dr. Onyia's primary specialty in the NPI Registry, under taxonomy code 207L00000X. Dmand AI has Dr. Onyia's licenses on file in 2 states: California and Arizona.
Specialties and state licenses
- Anesthesiology, CaliforniaPrimary
- Surgery, Arizona
Anesthesiologists near Dr. Onyia
Counts of anesthesiologists 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. Thomas K. Onyia billed Medicare for 129 services in 2024
CMS data shows 129 Medicare services from Dr. Onyia across 8 procedure codes in 2024, for 210 Medicare patients. Medicare paid $19,729 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Onyia's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Anesthesia
- 2023: 1072024: 1061%
- Surgery
- 2023: 162024: 2344%
Dr. Onyia compared with the California median for anesthesiologists, 2024
- Dr. Onyia
- California median
- Medicare services
- 129vs 7279% above
- Medicare patients
- 210vs 14347% above
Medians across 5,562 anesthesiologists in California with Dmand AI profiles that report each measure.
Dr. Onyia'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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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Onyia and other anesthesiologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Thomas K. Onyia treated 210 Medicare patients in 2024, average age 75
CMS counts 210 Medicare patients who saw Dr. Onyia in 2024. The largest group is 65 to 74, with 104 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 7% are also on Medicaid. Their average risk score is 1.26, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Dr. Onyia's median patient age at 51, with 67% women.
Dr. Onyia's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Dr. Onyia's Medicare patients by sex, 2024
- Women12158%
- Men8942%
Chronic conditions among Dr. Onyia's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis63%
- Atrial fibrillation27%
- Ischemic heart disease27%
- Mood disorders27%
- Cancer26%
- Anxiety24%
Share of Medicare patients with each condition. A patient can have several.
Dr. Onyia's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 51
Patient panel by sex, all payers
- Women67%
- Men33%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
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Dr. Thomas K. Onyia received $256 in industry payments in 2025
CMS Open Payments shows 2 general payments to Dr. Onyia from 2 drug and device companies in 2025. Food and beverage make up the largest share, 100% of the total. Vertex Pharmaceuticals Incorporated paid the most, $136.
Companies that paid Dr. Onyia the most, 2025 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Thomas K. Onyia graduated from University of California, San Diego School of Medicine
Dr. Onyia graduated from University of California, San Diego School of Medicine in 2015.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Thomas K. Onyia'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 DataDmand AI Org Hierarchy 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) |
| 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. Thomas K. Onyia
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. Thomas K. Onyia's NPI number?
Dr. Thomas K. Onyia's NPI number is 1902283443. It was assigned on May 5, 2015, and it is active in the NPI Registry.
What kind of doctor is Dr. Thomas K. Onyia?
Dr. Thomas K. Onyia is an anesthesiologist in Riverside, California. The primary specialty in the NPI Registry is Anesthesiology Physician (taxonomy code 207L00000X).
Where does Dr. Thomas K. Onyia practice?
Dr. Onyia practices at 10800 Magnolia Avenue, Riverside, CA 92505. Dr. Onyia's primary practice is Riverside Medical Center in Riverside, California, part of Kaiser Permanente.
What is Dr. Thomas K. Onyia's office phone number?
The practice phone on file for Dr. Onyia is (951) 353-2000.
What is Dr. Thomas K. Onyia's medical license number?
Dr. Onyia holds California license 149440, one of the licenses on file in 2 states.
Which states has Dr. Thomas K. Onyia been licensed in?
Dmand AI has state licenses on file for Dr. Onyia in California and Arizona.
Which hospitals is Dr. Thomas K. Onyia affiliated with?
Dr. Onyia practices at Riverside Medical Center in Riverside, California. Dr. Onyia is also affiliated with Hillcrest Medical Center.
What medical group is Dr. Thomas K. Onyia part of?
Dr. Onyia is linked to Southern California Permanente Medical Group.
Does Dr. Thomas K. Onyia accept Medicare?
Yes. CMS data shows Dr. Onyia billed Medicare for 129 services in 2024.
How many Medicare patients does Dr. Thomas K. Onyia see?
CMS counts 210 Medicare patients who saw Dr. Onyia in 2024, with an average age of 75.
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What services does Dr. Thomas K. Onyia bill to Medicare?
In 2024, Dr. Onyia's most billed Medicare services were surgery: brain, spine and nerves (64447), anesthesia (01402) and anesthesia (00731).
Where did Dr. Thomas K. Onyia go to medical school?
Dr. Onyia graduated from University of California, San Diego School of Medicine in 2015.
Has Dr. Thomas K. Onyia received payments from drug or device companies?
CMS Open Payments shows $256 in general payments to Dr. Onyia from 2 companies from 2025 to 2025. The largest total came from Vertex Pharmaceuticals Incorporated.
How long has Dr. Thomas K. Onyia been practicing?
Dr. Onyia graduated from medical school in 2015, 11 years ago.
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