William Marks, MD
NPI 1821023086 · Family Medicine Physician · Vista, CA
Enrolled with Medicare as Order and Referring Only - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Marks, MD is a Family Medicine Physician provider in Vista, CA (NPI 1821023086).
Provider details
- NPI number
- 1821023086
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- C31614 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 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
- 2006-07-12
- Last updated
- 2010-07-28
Frequently asked questions
- What is William Marks's NPI number?
- William Marks's National Provider Identifier (NPI) is 1821023086, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Marks's specialty?
- William Marks is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Marks located?
- William Marks's practice location on file with NPPES is 1000 Vale Terrace Dr, Vista, CA 92084-5218.
- What is William Marks's phone number?
- The practice phone number listed in the NPPES registry for William Marks is (760) 631-5000.
- Does William Marks accept Medicare?
- William Marks is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Marks's NPI active?
- Yes — William Marks's NPI (1821023086) is active in the NPPES registry as of the last update on 2010-07-28.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.