Dr. Diane E. Tjornhom, MD
- Medicare services, 2023
- 18
- Part D claims, 2024
- 2,020
- Industry payments
- $496
- Affiliated sites
- 4
- Medical groups
- 2
- Practice address
- 9400 Rosecrans Avenue, Bellflower, CA 90706
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Kaiser Permanente Medical Group Bellflower Medical Offices - HOPD
Acute Care Hospital outpatient department · Bellflower, California
Find Dr. Tjornhom'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. Diane E. Tjornhom is a rheumatologist in Bellflower, California
Dr. Tjornhom practices at Kaiser Permanente Medical Group Bellflower Medical Offices - HOPD in Bellflower, California.
Dr. Tjornhom's NPI, 1649339235, was assigned on December 8, 2006. Dr. Tjornhom graduated from University Of Minnesota Medical School in 1989. Dr. Tjornhom's California license number on file is G73827.
- NPI
- 1649339235NPI Registry (opens in a new tab)
- Medicare PAC ID
- 5698891794
- NPI enumeration date
- December 8, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Female
- Estimated age
- 63
- Medical school graduation
- 1989
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Diane E. Tjornhom practices at Kaiser Permanente Medical Group Bellflower Medical Offices - HOPD in Bellflower, California
Dr. Tjornhom's primary practice is Kaiser Permanente Medical Group Bellflower Medical Offices - HOPD, at 9400 Rosecrans Avenue, Bellflower, CA 90706.
- Kaiser Permanente Medical Group Bellflower Medical Offices - HOPD9400 Rosecrans Avenue, Bellflower, CA 90706
Source: Dmand AI Affiliation Data
Dr. Diane E. Tjornhom is affiliated with 4 sites of care and 2 medical groups
Dr. Tjornhom's primary practice is Kaiser Permanente Medical Group Bellflower Medical Offices - HOPD in Bellflower, California. The medical group on file is Southern California Permanente Medical Group. Dmand AI also links Dr. Tjornhom to 2 more group practices and clinics, 1 breast imaging center and 1 medical group, each named with a free account. Dr. Tjornhom's employer is on file too: a hospital.
Source: Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Diane E. Tjornhom's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Tjornhom practices, 4 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Kaiser Permanente Medical Group Bellflower Medical Offices - HOPD | Available with a free account |
| +3 more sites and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Diane E. Tjornhom is one of 821 rheumatologists in California
Rheumatology is Dr. Tjornhom's primary specialty in the NPI Registry, under taxonomy code 207RR0500X. Dr. Tjornhom is board certified in rheumatology by the American Board of Internal Medicine. Dmand AI has Dr. Tjornhom's licenses on file in 3 states: California, Hawaii and Florida.
Specialties and state licenses
- Rheumatology, CaliforniaPrimary
- Hawaii license
- Florida license
Clinical focus
Dmand AI lists arteritis, lupus and rheumatoid arthritis among the conditions Dr. Tjornhom treats.
Rheumatologists near Dr. Tjornhom
Counts of rheumatologists 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. Diane E. Tjornhom billed Medicare for 18 services in 2023
CMS data shows 18 Medicare services from Dr. Tjornhom across 1 procedure code in 2023, all of them office visits. Medicare paid $1,280 for them. Every service was in an office.
Dr. Tjornhom compared with the California median for rheumatologists, 2023
- Dr. Tjornhom
- California median
- Medicare services
- 18vs 90098% below
- Part D claims
- 1,730vs 96280% above
Medians across 773 rheumatologists in California with Dmand AI profiles that report each measure.
Dr. Tjornhom's most billed Medicare procedure codes, 2023
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. Tjornhom and other rheumatologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Diane E. Tjornhom's patients have a median age of 62
Across all payers, Dmand AI patient panel data puts Dr. Tjornhom's median patient age at 62, with 80% women.
Dr. Tjornhom's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 62
Patient panel by sex, all payers
- Women80%
- Men19%
Source: Dmand AI Patient Panel Data
Dr. Diane E. Tjornhom wrote 2,020 Medicare Part D claims in 2024
In 2024, Dr. Tjornhom wrote 2,020 Medicare Part D claims for 410 patients. 85% of them were for generic drugs. CMS names the drug for 1,730 of them, across 35 drugs with 11 or more claims each, at $922,403 in total drug cost. In 2023, CMS named 1,925 claims across 41 drugs.
Dr. Tjornhom's Part D claims by kind of drug, 2024
- Generic1,723 claims85%
- Brand-name and other297 claims15%
Dr. Tjornhom'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. Tjornhom's Part D claims, 2024
- Opioids11%215 of 2,020 claims
- Antibiotics1%12 of 2,020 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: 1,9252024: 1,73010%
Drugs named by CMS: 35 in 2024, 41 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
How Dr. Diane E. Tjornhom takes part in Medicare
Dr. Tjornhom accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Diane E. Tjornhom received $496 in industry payments from 2017 to 2023
CMS Open Payments shows 6 general payments to Dr. Tjornhom from 4 drug and device companies from 2017 to 2023. Food and beverage make up the largest share, 100% of the total. Bristol-Myers Squibb Company paid the most, $131.
General payments to Dr. Tjornhom by program year, 2017 to 2023
Companies that paid Dr. Tjornhom the most, 2017 to 2023
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Diane E. Tjornhom has 1 award and honors on record
Dmand AI lists 1 award for Dr. Tjornhom.
Awards and honors for Dr. Tjornhom
- Undated
- ACR Fellow
Source: Dmand AI Professional Profile Data
Dr. Diane E. Tjornhom graduated from University Of Minnesota Medical School
Dr. Tjornhom graduated from University Of Minnesota Medical School in 1989. Dr. Tjornhom is a member of ACP and ACR.
- Medical school
- Board certified in rheumatology
Source: Dmand AI Professional Profile Data
Dr. Diane E. Tjornhom accepts plans from 2 insurance carriers
Dr. Tjornhom is in network with 2 carriers, including Kaiser Permanente and CMS Medicare. EPO plans come from the most carriers, 1. Check the plan with the practice before a visit.
- Kaiser Permanente
- CMS Medicare
Plan types Dr. Tjornhom accepts, by number of carriers
- EPO1
- HMO1
- Medicare1
- POS1
Source: Dmand AI Insurance Network Data
Sources for Dr. Diane E. Tjornhom'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 Data |
| 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) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Awards and committee roles | Dmand AI Professional Profile Data |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| Insurance carriers and plan types | Dmand AI Insurance Network 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. Diane E. Tjornhom
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. Diane E. Tjornhom's NPI number?
Dr. Diane E. Tjornhom's NPI number is 1649339235. It was assigned on December 8, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Diane E. Tjornhom?
Dr. Diane E. Tjornhom is a rheumatologist in Bellflower, California. The primary specialty in the NPI Registry is Rheumatology Physician (taxonomy code 207RR0500X).
Where does Dr. Diane E. Tjornhom practice?
Dr. Tjornhom practices at 9400 Rosecrans Avenue, Bellflower, CA 90706. Dr. Tjornhom's primary practice is Kaiser Permanente Medical Group Bellflower Medical Offices - HOPD in Bellflower, California. Dmand AI also links Dr. Tjornhom to 2 group practices and clinics, 1 breast imaging center and 1 medical group.
What is Dr. Diane E. Tjornhom's medical license number?
Dr. Tjornhom's California license number on file is G73827, one of the licenses on file in 3 states.
Which states has Dr. Diane E. Tjornhom been licensed in?
Dmand AI has state licenses on file for Dr. Tjornhom in California (1992 to 2025), Hawaii (2024 to 2026) and Florida (1990 to 1994).
What medical group is Dr. Diane E. Tjornhom part of?
Dr. Tjornhom is linked to Southern California Permanente Medical Group. Dmand AI links Dr. Tjornhom to 1 more medical group.
Does Dr. Diane E. Tjornhom accept Medicare?
Yes. CMS data shows Dr. Tjornhom billed Medicare for 18 services in 2023, and Dr. Tjornhom accepts Medicare assignment.
Is Dr. Diane E. Tjornhom board certified?
Yes. Dr. Tjornhom is board certified in rheumatology by the American Board of Internal Medicine.
What services does Dr. Diane E. Tjornhom bill to Medicare?
In 2023, Dr. Tjornhom's most billed Medicare services were office visit, established patient (99214).
Where did Dr. Diane E. Tjornhom go to medical school?
Dr. Tjornhom graduated from University Of Minnesota Medical School in 1989.
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What drugs does Dr. Diane E. Tjornhom prescribe most?
In 2024 Medicare Part D data, Dr. Tjornhom's most prescribed drugs by claims were Methotrexate, Hydroxychloroquine Sulfate and Meloxicam.
Has Dr. Diane E. Tjornhom received payments from drug or device companies?
CMS Open Payments shows $496 in general payments to Dr. Tjornhom from 4 companies from 2017 to 2023. The largest total came from Bristol-Myers Squibb Company.
How long has Dr. Diane E. Tjornhom been practicing?
Dr. Tjornhom graduated from medical school in 1989, 37 years ago.
What insurance does Dr. Diane E. Tjornhom accept?
Dr. Tjornhom is in network with 2 carriers, including Kaiser Permanente and CMS Medicare. EPO plans come from the most carriers, 1. Check the plan with the practice before a visit.
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