NPPES file of Aug 9, 2026

Mark A. Hlavac, MD

Internal Medicine Physician · Walnut Creek, CA

Mark A. Hlavac, MD is an internal medicine physician with a practice address in Walnut Creek, California, and NPI 1255419354, issued on Nov 2, 2006. Check the license (California A62304, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1255419354
Name
Mark A. Hlavac
Credential
MD
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
A62304 CA
Self-reported in NPPES; status is on the state search
Practice location
320 Lennon LN, Walnut Creek, CA 94598
Phone
(925) 906-2000
Enumerated
Nov 2, 2006
Record last updated
Dec 13, 2021 (not updated in 5 years: call before relying on the address or phone)
Medicaid ID
00A623040 CA
Medicare enrollment
Enrolled (PECOS I20110201000000); accepts Medicare assignment
Medical or professional school
Temple University School Of Medicine, 1995
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 320 Lennon LN

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Joel Acab, MDInternal Medicine Physician1518405661
  2. Vitas Alekna, MDOphthalmology Physician1770661860
  3. Mary Andre, P.T.Physical Therapist1740344779
  4. Lynn Arsenault, MDPediatrics Physician1972681054
  5. Ashley Batchelder, DPTPhysical Therapist1851450936
  6. Cynthia Bellitt, R.N.N.P.Women's Health Nurse Practitioner1851464630

Verify Mark A. Hlavac in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A62304
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the California license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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6% more Medicare Part D claims than the average internal medicine physician in 2024

3,380 Medicare Part D claims for 493 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 129 claims were for opioids.

  1. Mark Hlavac3,380
  2. Specialty average3,176

Most prescribed

  1. Atorvastatin Calcium181 claims
  2. Amlodipine Besylate156 claims
  3. Losartan Potassium124 claims
  4. Lisinopril110 claims
  5. Levothyroxine Sodium104 claims
  6. Fluticasone Propionate103 claims

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

Bills Medicare through one group practice

  1. Permanente Medical Group IncWalnut Creek, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Mark A. Hlavac among 17,696 internal medicine physician records in California

Mark A. Hlavac, MD is one of 17,696 internal medicine physician records with a practice address in California. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 5% of them.

  • NPI issued2006 · 5% of these records are older, 56% newer
  • In a Medicare fileYes · 79% of these records are
  • In the CMS Doctors and Clinicians fileYes · 63% of these records are
  • Graduated1995 · median 2004 among the 11,065 with a school on file
  • Record last updated2021 · 61% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

183 internal medicine physician records list a practice address in Walnut Creek

They are 183 of the 6,170 NPPES records with a practice address in Walnut Creek, and 17,696 internal medicine physician records in California.

The 8 internal medicine physician records with the nearest ZIP codes

  1. Anthony Bernens, MDWalnut Creek, CA 945981215983440
  2. Martin Braker, M.D.Walnut Creek, CA 945981922050095
  3. Mei Chow-Kwan, MDWalnut Creek, CA 945981689619330
  4. Lisa Craig, MDWalnut Creek, CA 945981699853754
  5. Jaya Francis, MDWalnut Creek, CA 945981962580548
  6. Tarannum Guller, MDWalnut Creek, CA 945981972532083
  7. Noushin Haddad-Tehrani, MDWalnut Creek, CA 945981215988878
  8. Waheeda Hiller, MDWalnut Creek, CA 945981689642233

Common questions

What is Mark A. Hlavac, MD's NPI number?

Mark A. Hlavac, MD's National Provider Identifier (NPI) is 1255419354, issued on Nov 2, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Mark A. Hlavac, MD located?

The NPPES record lists a practice address at 320 Lennon LN, Walnut Creek, CA, 94598. Phone: (925) 906-2000. Providers update this record themselves, so call before visiting.

How can I verify Mark A. Hlavac, MD's license?

NPPES lists California license number A62304, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

How much does Mark A. Hlavac, MD prescribe under Medicare Part D?

In 2024, Mark A. Hlavac, MD had 3,380 Medicare Part D claims for 493 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.