Physician Profile

William Sierra, M.D.

Unclaimed Profile

About Dr. Sierra

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Specialty

Ophthalmology (Primary)

Credentials & Licensing

CA licenseG32593
NPI1275552796
NPI issued07/18/2006

License numbers are what the provider reported to NPPES when the NPI was issued or updated. NPPES does not verify licensure; confirm current standing with the state licensing board.

Medicare information

Medicare opt-outNo
Can order and refer in MedicareYes

Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.

Common questions

What does William Sierra specialize in?

William Sierra is an eye doctor in Los Angeles, CA. That is the designation recorded for this NPI in the federal registry, where it is listed as “Ophthalmology”.

NPI registry

Where is William Sierra located?

William Sierra is listed at 4754 E Cesar E Chavez Ave, Los Angeles, CA 90022. Addresses come from the NPI registry and can lag a move, so confirm before travelling.

NPI registry

What is William Sierra's phone number?

The number on file is (323) 909-0041. Guide.md cannot book appointments or pass on messages — please call the office directly.

NPI registry

What is William Sierra's NPI number?

William Sierra's National Provider Identifier is 1275552796. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.

NPI registry

How long has William Sierra been practicing?

William Sierra has 20+ years experience. Registered with an NPI since 2006. National Provider Identifiers only began in 2005, so a provider who qualified earlier may have practiced for longer than this.

NPI registry

Has William Sierra confirmed this information?

Not yet. This profile is built from public federal data and has not been confirmed by William Sierra. If this is you, claiming it is free.

Guide.md

Provider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.