Mark Christiansen, MD
NPI 1821108218 · Endocrinology, Diabetes & Metabolism Physician · Walnut Creek, CA
Enrolled with Medicare as Practitioner - Endocrinology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Christiansen, MD is a Endocrinology, Diabetes & Metabolism Physician provider in Walnut Creek, CA (NPI 1821108218).
Provider details
- NPI number
- 1821108218
- Entity type
- Individual
- Primary specialty
- Endocrinology, Diabetes & Metabolism PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G62892 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
19 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
2 documented practice locations
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$479 across 5 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (1)
- 5725 W Las Positas Blvd#210Pleasanton, CA 94588-4007Phone: (925) 463-1400Fax: (925) 251-9026
Registry dates
- Enumerated
- 2006-08-30
- Last updated
- 2021-06-23
- Certified
- 2021-06-23
Frequently asked questions
- What is Mark Christiansen's NPI number?
- Mark Christiansen's National Provider Identifier (NPI) is 1821108218, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Christiansen's specialty?
- Mark Christiansen is listed in the NPPES registry with a primary specialty of Endocrinology, Diabetes & Metabolism Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Christiansen located?
- Mark Christiansen's practice location on file with NPPES is 2405 Shadelands Dr Ste 300, Walnut Creek, CA 94598-5906.
- What is Mark Christiansen's phone number?
- The practice phone number listed in the NPPES registry for Mark Christiansen is (925) 939-8585.
- Does Mark Christiansen accept Medicare?
- Mark Christiansen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Christiansen's NPI active?
- Yes — Mark Christiansen's NPI (1821108218) is active in the NPPES registry as of the last update on 2021-06-23.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.