Mark Hlavac, MD
NPI 1255419354 · Internal Medicine Physician · Walnut Creek, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Hlavac, MD is a Internal Medicine Physician provider in Walnut Creek, CA (NPI 1255419354).
Provider details
- NPI number
- 1255419354
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A62304 (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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 75 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 181 | 83 |
| Amlodipine Besylate | 156 | 69 |
| Losartan Potassium | 124 | 54 |
| Lisinopril | 110 | 49 |
| Levothyroxine Sodium | 104 | 42 |
| Fluticasone Propionate | 103 | 41 |
| Albuterol Sulfate |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-11-02
- Last updated
- 2021-12-13
Frequently asked questions
- What is Mark Hlavac's NPI number?
- Mark Hlavac's National Provider Identifier (NPI) is 1255419354, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Hlavac's specialty?
- Mark Hlavac is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Hlavac located?
- Mark Hlavac's practice location on file with NPPES is 320 Lennon Ln, Walnut Creek, CA 94598-2419.
- What is Mark Hlavac's phone number?
- The practice phone number listed in the NPPES registry for Mark Hlavac is (925) 906-2000.
- Does Mark Hlavac accept Medicare?
- Mark Hlavac is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Hlavac's NPI active?
- Yes — Mark Hlavac's NPI (1255419354) is active in the NPPES registry as of the last update on 2021-12-13.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.