Dr. Rex Chen Hsei, MD
- Medicare services, 2024
- 4,103
- Medicare patients, 2024
- 1,829
- Part D claims, 2024
- 2,377
- MIPS score, 2024
- 98
- Industry payments
- $1,497
- Practice address
- 1665 Dominican Way, Santa Cruz, CA 95065
- Practice phone
- Call (831) 476-6943
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Cypress Outpatient Surgical Center, Inc.
Santa Cruz, California
Find Dr. Hsei'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. Rex Chen Hsei is an ophthalmologist in Santa Cruz, California
Dr. Hsei practices at Cypress Outpatient Surgical Center, Inc. in Santa Cruz, California.
Dr. Hsei's NPI, 1285637157, was assigned on May 24, 2005. Dr. Hsei graduated from MCP-Hahnemann College of Medicine in 1996. Dr. Hsei holds California license A71449.
- NPI
- 1285637157NPI Registry (opens in a new tab)
- Medicare PAC ID
- 8628168853
- NPI enumeration date
- May 24, 2005
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (831) 476-6943
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 56
- Medical school graduation
- 1996
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Practice Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Rex Chen Hsei practices at Cypress Outpatient Surgical Center, Inc. in Santa Cruz, California
Dr. Hsei's primary practice is Cypress Outpatient Surgical Center, Inc., at 1665 Dominican Way, Santa Cruz, CA 95065 in Santa Cruz County. The practice phone is (831) 476-6943.
- Cypress Outpatient Surgical Center, Inc.1665 Dominican Way, Santa Cruz, CA 95065 · Santa Cruz CountyPhone(831) 476-6943
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. Rex Chen Hsei is affiliated with 2 sites of care and 1 medical group
Dr. Hsei's primary practice is Cypress Outpatient Surgical Center, Inc. in Santa Cruz, California. Dmand AI also links Dr. Hsei to 1 group practice or clinic and 1 medical group, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Rex Chen Hsei's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Hsei practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Cypress Outpatient Surgical Center, Inc. | Available with a free account |
| +1 more site and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Rex Chen Hsei is one of 2,621 ophthalmologists in California
Ophthalmology is Dr. Hsei's primary specialty in the NPI Registry, under taxonomy code 207W00000X. Dr. Hsei is board certified in ophthalmology by the American Board of Ophthalmology. Dmand AI has Dr. Hsei's licenses on file in 2 states: California and Pennsylvania.
Specialties and state licenses
- Ophthalmology, CaliforniaPrimary
- Pennsylvania license
Clinical focus
Dmand AI lists age-related macular degeneration, cataract, cataract surgery with lens implant, conjunctivitis, dry eye, eyelid inflammation, glaucoma and glaucoma surgery among the conditions Dr. Hsei treats.
Ophthalmologists near Dr. Hsei
Counts of ophthalmologists 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. Rex Chen Hsei billed Medicare for 4,103 services in 2024
CMS data shows 4,103 Medicare services from Dr. Hsei across 13 procedure codes in 2024, for 1,829 Medicare patients. Medicare paid $437,888 for them.
Dr. Hsei's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Tests and treatments
- 2023: 3,4192024: 3,3622%
- Surgery
- 2023: 4182024: 45910%
- Office and hospital visits
- 2023: 1132024: 257127%
- Imaging
- 2023: 292024: 2514%
Where Dr. Hsei's Medicare services took place, 2024
- In an office3,71090%
- In a facility39310%
Dr. Hsei compared with the California median for ophthalmologists, 2024
- Dr. Hsei
- California median
- Medicare services
- 4,103vs 1,0793.8 times
- Medicare patients
- 1,829vs 4214.3 times
- Part D claims
- 2,322vs 6183.8 times
Medians across 2,568 ophthalmologists in California with Dmand AI profiles that report each measure.
Dr. Hsei'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. Hsei and other ophthalmologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Rex Chen Hsei treated 1,829 Medicare patients in 2024, average age 75
CMS counts 1,829 Medicare patients who saw Dr. Hsei in 2024. The largest group is 65 to 74, with 798 patients. 70% of them have high cholesterol, and 68% have high blood pressure. 33% are also on Medicaid. Their average risk score is 1.12, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Dr. Hsei's median patient age at 64, with 55% women.
Dr. Hsei's Medicare patients by age, 2024
Dr. Hsei's Medicare patients by sex, 2024
- Women1,09760%
- Men73240%
Chronic conditions among Dr. Hsei's Medicare patients, 2024
- High cholesterol70%
- High blood pressure68%
- Arthritis40%
- Diabetes34%
- Mood disorders19%
- Chronic kidney disease18%
- Osteoporosis18%
- Anxiety17%
Share of Medicare patients with each condition. A patient can have several.
Dr. Hsei's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 64
Patient panel by sex, all payers
- Women55%
- Men44%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Rex Chen Hsei wrote 2,377 Medicare Part D claims in 2024
In 2024, Dr. Hsei wrote 2,377 Medicare Part D claims for 527 patients. 59% of them were for generic drugs. CMS names the drug for 2,322 of them, across 24 drugs with 11 or more claims each, at $236,208 in total drug cost. In 2023, CMS named 2,455 claims across 24 drugs.
Dr. Hsei's Part D claims by kind of drug, 2024
- Generic1,403 claims59%
- Brand-name974 claims41%
Dr. Hsei'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.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 2,4552024: 2,3225%
Drugs named by CMS: 24 in 2024, 24 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
Dr. Rex Chen Hsei scored 98 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 98 out of 100 for Dr. Hsei for performance year 2024, reported individually. Dr. Hsei accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS counts 671 procedures of cataract surgery by Dr. Hsei, more than 97% of the clinicians it reports for that procedure.
- Accepts Medicare assignment
- Yes
Dr. Hsei's MIPS scores, performance year 2024
- 98of 100Final score
- 100of 100Quality
- 40of 100Improvement Activities
- 78of 100Cost
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
Where Dr. Hsei ranks in Medicare procedure volume
- Cataract surgery
- 97th percentile671 procedures
CMS ranks each clinician against every clinician it reports for the same procedure category.
Sources: Doctors and Clinicians National Downloadable File (CMS); Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026; and Doctors and Clinicians Utilization Data (CMS)
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Dr. Rex Chen Hsei received $1,497 in industry payments from 2016 to 2025
CMS Open Payments shows 40 general payments to Dr. Hsei from 16 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 94% of the total. Alcon Laboratories Inc paid the most, $299.
General payments to Dr. Hsei by program year, 2016 to 2025
General payments to Dr. Hsei by kind, 2016 to 2025
- Food and beverage$1,40294%
- Education$755%
- Gifts$191%
Companies that paid Dr. Hsei the most, 2016 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Rex Chen Hsei graduated from MCP-Hahnemann College of Medicine
Dr. Hsei graduated from MCP-Hahnemann College of Medicine in 1996.
- Medical school
- Board certified in ophthalmology
Source: Dmand AI Professional Profile Data
Dr. Rex Chen Hsei accepts plans from 10 insurance carriers
Dr. Hsei is in network with 10 carriers, including Aetna, Blue Cross Blue Shield of Michigan and United Healthcare. Medicare plans come from the most carriers, 7. Check the plan with the practice before a visit.
- Aetna
- Blue Cross Blue Shield of Michigan
- United Healthcare
- Blue Cross Blue Shield of Massachusetts
- Elevance
- HCSC
- Regence Health Plans
- Aspirus Health Plan
- +2 more carriersWith a free account
Plan types Dr. Hsei accepts, by number of carriers
- Medicare7
- PPO7
- POS4
- EPO3
- HMO3
Source: Dmand AI Insurance Network Data
Sources for Dr. Rex Chen Hsei'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 | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand 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) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab)Clinician Public Reporting: Overall MIPS Performance (CMS) (opens in a new tab)Doctors and Clinicians Utilization Data (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 |
| 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. Rex Chen Hsei
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. Rex Chen Hsei's NPI number?
Dr. Rex Chen Hsei's NPI number is 1285637157. It was assigned on May 24, 2005, and it is active in the NPI Registry.
What kind of doctor is Dr. Rex Chen Hsei?
Dr. Rex Chen Hsei is an ophthalmologist in Santa Cruz, California. The primary specialty in the NPI Registry is Ophthalmology Physician (taxonomy code 207W00000X).
Where does Dr. Rex Chen Hsei practice?
Dr. Hsei practices at 1665 Dominican Way, Santa Cruz, CA 95065. Dr. Hsei's primary practice is Cypress Outpatient Surgical Center, Inc. in Santa Cruz, California. Dmand AI also links Dr. Hsei to 1 group practice or clinic and 1 medical group.
What is Dr. Rex Chen Hsei's office phone number?
The practice phone on file for Dr. Hsei is (831) 476-6943.
What is Dr. Rex Chen Hsei's medical license number?
Dr. Hsei holds California license A71449, one of the licenses on file in 2 states.
Which states has Dr. Rex Chen Hsei been licensed in?
Dmand AI has state licenses on file for Dr. Hsei in California (2000 to 2026) and Pennsylvania (1998 to 2000).
Does Dr. Rex Chen Hsei accept Medicare?
Yes. CMS data shows Dr. Hsei billed Medicare for 4,103 services in 2024, and Dr. Hsei accepts Medicare assignment.
What is Dr. Rex Chen Hsei's MIPS score?
Dr. Hsei's MIPS final score for performance year 2024 is 98 out of 100, reported individually.
How many Medicare patients does Dr. Rex Chen Hsei see?
CMS counts 1,829 Medicare patients who saw Dr. Hsei in 2024, with an average age of 75.
Is Dr. Rex Chen Hsei board certified?
Yes. Dr. Hsei is board certified in ophthalmology by the American Board of Ophthalmology.
Show 6 more questionsShow fewer questions
What services does Dr. Rex Chen Hsei bill to Medicare?
In 2024, Dr. Hsei's most billed Medicare services were eye exam or test (92014), eye exam or test (92012) and eye exam or test (92136).
Where did Dr. Rex Chen Hsei go to medical school?
Dr. Hsei graduated from MCP-Hahnemann College of Medicine in 1996.
What drugs does Dr. Rex Chen Hsei prescribe most?
In 2024 Medicare Part D data, Dr. Hsei's most prescribed drugs by claims were Latanoprost, Prednisolone Acetate and Ofloxacin.
Has Dr. Rex Chen Hsei received payments from drug or device companies?
CMS Open Payments shows $1,497 in general payments to Dr. Hsei from 16 companies from 2016 to 2025. The largest total came from Alcon Laboratories Inc.
How long has Dr. Rex Chen Hsei been practicing?
Dr. Hsei graduated from medical school in 1996, 30 years ago.
What insurance does Dr. Rex Chen Hsei accept?
Dr. Hsei is in network with 10 carriers, including Aetna, Blue Cross Blue Shield of Michigan and United Healthcare. Medicare plans come from the most carriers, 7. Check the plan with the practice before a visit.
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