Stephen Kalkstein, MD
NPI 1356438113 · Family Medicine Physician · Martinez, CA
Enrolled with Medicare as Order and Referring Only - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Stephen Kalkstein, MD is a Family Medicine Physician provider in Martinez, CA (NPI 1356438113).
Provider details
- NPI number
- 1356438113
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G25872 (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
- 2006-10-05
- Last updated
- 2007-07-08
Frequently asked questions
- What is Stephen Kalkstein's NPI number?
- Stephen Kalkstein's National Provider Identifier (NPI) is 1356438113, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Stephen Kalkstein's specialty?
- Stephen Kalkstein is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Stephen Kalkstein located?
- Stephen Kalkstein's practice location on file with NPPES is 2500 Alhambra Avenue, Martinez, CA 94553-3156.
- What is Stephen Kalkstein's phone number?
- The practice phone number listed in the NPPES registry for Stephen Kalkstein is (925) 370-5110.
- Does Stephen Kalkstein accept Medicare?
- Stephen Kalkstein is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Stephen Kalkstein's NPI active?
- Yes — Stephen Kalkstein's NPI (1356438113) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.