Mark Carlton Rounsaville, MD
Radiation Oncology Physician · Nicasio, CA
Mark Carlton Rounsaville, MD is a radiation oncology physician with a practice address in Nicasio, California, and NPI 1033100284, issued on Nov 4, 2005. Check the license (California A39060, as entered in NPPES) on the Medical Board of California; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- Mark Carlton Rounsaville
- Credential
- MD
- Primary taxonomy
- Radiation Oncology Physician 2085R0001X
- License number
- A39060 CA
Self-reported in NPPES; status is on the state search - Practice location
- 45 Los Pinos, Nicasio, CA 94946
- Phone
- (415) 662-2669
- Enumerated
- Nov 4, 2005
- Record last updated
- May 17, 2022
- Fax
- (415) 662-2669
- Medicaid ID
- 00A390600 CA
- Entity
- Type 1 · individual
8 nearest radiation oncology physician records → All 735 in California → Look up another NPI →
Verify Mark Carlton Rounsaville in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A39060Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Mark Carlton Rounsaville among 735 radiation oncology physician records in California
Mark Carlton Rounsaville, MD is one of 735 radiation oncology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 84% newer
- In a Medicare fileNo · 83% of these records are
- In the CMS Doctors and Clinicians fileNo · 74% of these records are
- Record last updated2022 · 55% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0001X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Radiation Oncology Physician providers in California
There are 735 radiation oncology physician records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 735 in California → Radiation Oncology Physician nationwide →
The 8 radiation oncology physician records with the nearest ZIP codes
- Marc Fields, MDRohnert Park, CA 949281730143066
- Peter Hawkins, M.D., PH.D.Rohnert Park, CA 949281962820621
- Irwin Lee, MDRohnert Park, CA 949281861510760
- Nikhil Rao, MDRohnert Park, CA 949281275737850
- Allan Rappaport, M.D., J.D.Tiburon, CA 949201346310539
- Francine Halberg, MDGreenbrae, CA 949041275515256
- Lloyd Miyawaki, MDGreenbrae, CA 949041497737464
- Joseph Poen, MDGreenbrae, CA 949041972585941
Common questions
What is Mark Carlton Rounsaville, MD's NPI number?
Mark Carlton Rounsaville, MD's National Provider Identifier (NPI) is 1033100284, issued on Nov 4, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Mark Carlton Rounsaville, MD located?
The NPPES record lists a practice address at 45 Los Pinos, Nicasio, CA, 94946. Phone: (415) 662-2669. Providers update this record themselves, so call before visiting.
How can I verify Mark Carlton Rounsaville, MD's license?
NPPES lists California license number A39060, 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.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. 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.