Dr. William Sierra, MD
- Medicare services, 2022
- 76
- Part D claims, 2024
- 19
- Insurance carriers
- 8
- State license
- 1
- Year NPI issued
- 2006
- Practice address
- 4754 E Cesar E Chavez Ave, Los Angeles, CA 90022-1234
- Practice phone
- Call (323) 909-0041
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Find Dr. Sierra'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. William Sierra is an ophthalmologist in Los Angeles, California
Dr. Sierra practices in Los Angeles, California.
Dr. Sierra's NPI, 1275552796, was assigned on July 18, 2006. Dr. Sierra graduated from Loma Linda University School Of Medicine in 1975. Dr. Sierra's California license number on file is G32593.
- NPI
- 1275552796NPI Registry (opens in a new tab)
- NPI enumeration date
- July 18, 2006
- NPI status
- Active
- Practice phone
- (323) 909-0041
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 77
- Medical school graduation
- 1975
Sources: NPPES NPI Registry (CMS); and Dmand AI Professional Profile Data
Dr. William Sierra's practice address is in Los Angeles, California
Dr. Sierra's practice address in the NPI Registry is 4754 E Cesar E Chavez Ave, Los Angeles, CA 90022-1234. The practice phone is (323) 909-0041.
- NPI Registry address4754 E Cesar E Chavez Ave, Los Angeles, CA 90022-1234Phone(323) 909-0041
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dmand AI tracks the EHR system at Dr. William Sierra's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Sierra practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Dr. Sierra's practice | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. William Sierra is one of 2,621 ophthalmologists in California
Ophthalmology is Dr. Sierra's primary specialty in the NPI Registry, under taxonomy code 207W00000X. Dr. Sierra is board certified in ophthalmology by the American Board of Ophthalmology. Dr. Sierra has a license on file in California.
Specialties and state licenses
- Ophthalmology, CaliforniaPrimary
Clinical focus
Dmand AI lists conjunctivitis, dry eye, eye infection or inflammation, eyelid inflammation and glaucoma among the conditions Dr. Sierra treats.
Ophthalmologists near Dr. Sierra
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. William Sierra billed Medicare for 76 services in 2022
CMS data shows 76 Medicare services from Dr. Sierra across 2 procedure codes in 2022. Medicare paid $5,186 for them. Every service was in an office.
Dr. Sierra's Medicare services by type, 2021 to 2022
- 2021
- 2022
- Office and hospital visits
- 2021: 332022: 4536%
- Tests and treatments
- 2021: 372022: 3116%
Dr. Sierra compared with the California median for ophthalmologists, 2022
- Dr. Sierra
- California median
- Medicare services
- 76vs 1,07993% below
- Part D claims
- 77vs 61888% below
Medians across 2,568 ophthalmologists in California with Dmand AI profiles that report each measure.
Dr. Sierra's most billed Medicare procedure codes, 2022
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. Sierra and other ophthalmologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. William Sierra's patients have a median age of 70
Across all payers, Dmand AI patient panel data puts Dr. Sierra's median patient age at 70, with 33% women.
Dr. Sierra's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 70
Patient panel by sex, all payers
- Women33%
- Men67%
Source: Dmand AI Patient Panel Data
Dr. William Sierra wrote 19 Medicare Part D claims in 2024
In 2024, Dr. Sierra wrote 19 Medicare Part D claims. They cover 3 drugs, with $52,585 in total drug cost. In 2022, CMS named 193 claims across 6 drugs.
Dr. Sierra's most prescribed drugs by claims, 2023
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, 2022 to 2023
- 2022
- 2023
- Claims for drugs CMS names
- 2022: 1932023: 7760%
Drugs named by CMS: 3 in 2023, 6 in 2022.
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. William Sierra graduated from Loma Linda University School Of Medicine
Dr. Sierra graduated from Loma Linda University School Of Medicine in 1975.
- Medical school
- Board certified in ophthalmology
Source: Dmand AI Professional Profile Data
Dr. William Sierra accepts plans from 8 insurance carriers
Dr. Sierra is in network with 8 carriers, including Aetna, Humana and Blue Cross Blue Shield of Massachusetts. Medicare plans come from the most carriers, 8. Check the plan with the practice before a visit.
- Aetna
- Humana
- Blue Cross Blue Shield of Massachusetts
- Blue Cross Blue Shield of Michigan
- Elevance
- HCSC
- Molina
- Regence Health Plans
Plan types Dr. Sierra accepts, by number of carriers
- Medicare8
- PPO7
- HMO3
- EPO1
- POS1
Source: Dmand AI Insurance Network Data
Sources for Dr. William Sierra'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 |
| 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) |
| 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. William Sierra
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. William Sierra's NPI number?
Dr. William Sierra's NPI number is 1275552796. It was assigned on July 18, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. William Sierra?
Dr. William Sierra is an ophthalmologist in Los Angeles, California. The primary specialty in the NPI Registry is Ophthalmology Physician (taxonomy code 207W00000X).
Where does Dr. William Sierra practice?
Dr. Sierra practices at 4754 E Cesar E Chavez Ave, Los Angeles, CA 90022-1234.
What is Dr. William Sierra's office phone number?
The practice phone on file for Dr. Sierra is (323) 909-0041.
What is Dr. William Sierra's medical license number?
Dr. Sierra's California license number on file is G32593.
Does Dr. William Sierra accept Medicare?
Yes. CMS data shows Dr. Sierra billed Medicare for 76 services in 2022.
Is Dr. William Sierra board certified?
Yes. Dr. Sierra is board certified in ophthalmology by the American Board of Ophthalmology.
What services does Dr. William Sierra bill to Medicare?
In 2022, Dr. Sierra's most billed Medicare services were office visit, established patient (99213) and eye exam or test (92012).
Where did Dr. William Sierra go to medical school?
Dr. Sierra graduated from Loma Linda University School Of Medicine in 1975.
What drugs does Dr. William Sierra prescribe most?
In 2023 Medicare Part D data, Dr. Sierra's most prescribed drugs by claims were Alphagan P, Lumigan and Xiidra.
How long has Dr. William Sierra been practicing?
Dr. Sierra graduated from medical school in 1975, 51 years ago.
What insurance does Dr. William Sierra accept?
Dr. Sierra is in network with 8 carriers, including Aetna, Humana and Blue Cross Blue Shield of Massachusetts. Medicare plans come from the most carriers, 8. Check the plan with the practice before a visit.
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