Registry data as of Aug 27, 2026

Mark Olson, RPH

Pharmacist · Sebastopol, CA

Mark Olson, RPH is a pharmacist with a practice address in Sebastopol, California, and NPI 1831224468, issued on Feb 23, 2007. Check the license with the California board that licenses this profession; the Medicare figures below come from public CMS files.

Record from CMS NPPES, loaded Aug 27, 2026 · Medicare files 2023 and 2024 · method · Verify with CMS →

NPPES recordas of Aug 27, 2026
1831224468
Name
Mark Olson
Credential
RPH
Primary taxonomy
Pharmacist 183500000X
Practice location
218 N Main St, Sebastopol, CA 95472
Phone
(707) 829-3007
Enumerated
Feb 23, 2007
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 218 N Main St

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

  1. Marny GuangcoPharmacist1982932943
  2. Barbara Jason, PHARMACY TECHNICIANPharmacy Technician1245933456
  3. Bumsoo KimPharmacist1518477801
  4. Eunhye KwonPharmacist1023486669
  5. Areen SawagedPharmacist1922702836

Verify Mark Olson in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich California board licenses this professionCheck 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
Find 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.

Statewide context: the Medical Board of California reported 374 disciplinary actions in FY 2022-23. California discipline data →

69% fewer Medicare Part D claims than the average pharmacist in 2024

40 Medicare Part D claims for 32 beneficiaries, against an average of 127 among the 28,933 providers of this specialty who prescribed in Part D. Brand-name drugs were 100% of claims.

  1. Mark Olson40
  2. Specialty average127

Most prescribed

  1. Shingrix19 claims
  2. Abrysvo16 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.

18 pharmacist records list a Sebastopol practice address

They are 18 of the 550 NPPES records with a Sebastopol practice address, and 32,698 pharmacist records in California.

Other pharmacist records in California

  1. Caroline A-Haja, PHARM.D.San Pedro, CA1851664361
  2. Gayatri AachiLivermore, CA1235660754
  3. Adrian Karlos Aala, PHARMD, RPHHayward, CA1023955499
  4. Mahshid Aalam, PHARMDLos Angeles, CA1659086155
  5. Jaleh AaliiveliSan Ramon, CA1336629963
  6. Cassi Aarvig, RPHTracy, CA1023679941
  7. Meara Michi AbadOrange, CA1750181178
  8. Nader Abadier, RPHFontana, CA1326255647
  9. Samia Abadier, RPHFontana, CA1548742836
  10. Sandy Abadir, RPHChino Hills, CA1811644412

Common questions

What is Mark Olson, RPH's NPI number?

Mark Olson, RPH's National Provider Identifier (NPI) is 1831224468, issued on Feb 23, 2007. An NPI identifies a provider in billing; it is not a license.

Where is Mark Olson, RPH located?

The NPPES record lists a practice address at 218 N Main St, Sebastopol, CA, 95472. Phone: (707) 829-3007. Providers update this record themselves, so call before visiting.

How can I verify Mark Olson, RPH's license?

Search the California board that licenses this profession; the NPPES record confirms identity only.

How much does Mark Olson, RPH prescribe under Medicare Part D?

In 2024, Mark Olson, RPH had 40 Medicare Part D claims for 32 beneficiaries; the average among pharmacist prescribers was 127. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), loaded Aug 27, 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.

Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 27, 2026.