William Lyon, MD
NPI 1245423946 · Clinic/Center · Laguna Niguel, CA
William Lyon, MD is a Clinic/Center provider in Laguna Niguel, CA (NPI 1245423946).
Provider details
- NPI number
- 1245423946
- Entity type
- Individual
- Primary specialty
- Clinic/CenterAmbulatory Health Care Facilities
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- C27618 (CA)
Specialties & taxonomies
Ambulatory Health Care Facilities
Ambulatory Health Care Facilities
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
18 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-08-25
- Last updated
- 2026-04-26
Frequently asked questions
- What is William Lyon's NPI number?
- William Lyon's National Provider Identifier (NPI) is 1245423946, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Lyon's specialty?
- William Lyon is listed in the NPPES registry with a primary specialty of Clinic/Center (Ambulatory Health Care Facilities).
- Where is William Lyon located?
- William Lyon's practice location on file with NPPES is 30110 Crown Valley Pkwy, Laguna Niguel, CA 92677-2043.
- What is William Lyon's phone number?
- The practice phone number listed in the NPPES registry for William Lyon is (949) 495-7144.
- Is William Lyon's NPI active?
- Yes — William Lyon's NPI (1245423946) is active in the NPPES registry as of the last update on 2026-04-26.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.