NPPES file of Aug 9, 2026

Mark Steven Agness, M.D.

Family Medicine Physician · Marysville, CA

Mark Steven Agness, M.D. is a family medicine physician with a practice address in Marysville, California, and NPI 1609816743, issued on Jun 7, 2006. Check the license (California G68116, 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
1609816743
Name
Mark Steven Agness
Credential
M.D.
Primary taxonomy
Family Medicine Physician 207Q00000X
License number
G68116 CA
Self-reported in NPPES; status is on the state search
Practice location
726 4TH Street, Marysville, CA 94901
Phone
(530) 749-4300
Enumerated
Jun 7, 2006
Record last updated
Aug 27, 2007 (not updated in 19 years: call before relying on the address or phone)
Medicaid ID
00G681160 CA
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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Also registered at 726 4TH Street

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

  1. Pamela Fallo, C.F.N.PRegistered Nurse1689612921
  2. Katherine Kelly, N.PFamily Nurse Practitioner1679517205
  3. Robert Martin, M.DEmergency Medicine Physician1205876208
  4. Robert Olson, P.A-CPhysician Assistant1932147287
  5. Alexandra Reichman, M.D.Anatomic Pathology & Clinical Pathology Physician1639208721
  6. Steven Segerstrom, M.DFamily Medicine Physician1205876240

Verify Mark Steven Agness in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G68116
    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

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100% fewer Medicare Part D claims than the average family medicine physician in 2024

12 Medicare Part D claims, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D.

  1. Mark Agness12
  2. Specialty average3,544

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.

Family Medicine Physician providers in California

There are 17,133 family medicine physician records in California.

Other family medicine physician records in California

  1. Omer Aba-Omer, MDSanta Monica, CA1649702093
  2. Michelle Ababa, MDWilmington, CA1710922513
  3. Anna Tzeitel Abalos, MDRoseville, CA1720200017
  4. Adan Abarca, MDAnaheim, CA1760553689
  5. Vanessa Abarca, DOVentura, CA1952040859
  6. Lorraine Abate, M.D.Sacramento, CA1104840008
  7. Robert Abatecola, MDCastro Valley, CA1669551719
  8. Romeo Abaya, M.D.Cottonwood, CA1598053506
  9. Effiem Abbah, MD, MPHSan Francisco, CA1821185133
  10. Khuzeman Abbasi, MDSanta Rosa, CA1841979952

Common questions

What is Mark Steven Agness, M.D.'s NPI number?

Mark Steven Agness, M.D.'s National Provider Identifier (NPI) is 1609816743, issued on Jun 7, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Mark Steven Agness, M.D. located?

The NPPES record lists a practice address at 726 4TH Street, Marysville, CA, 94901. Phone: (530) 749-4300. Providers update this record themselves, so call before visiting.

How can I verify Mark Steven Agness, M.D.'s license?

NPPES lists California license number G68116, 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 Steven Agness, M.D. prescribe under Medicare Part D?

In 2024, Mark Steven Agness, M.D. had 12 Medicare Part D claims; the average among family medicine physician prescribers was 3,544. 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.