Robert Ryn Johnson, M.D.
Therapeutic Radiology Physician · San Luis Obispo, CA
Robert Ryn Johnson, M.D. is a therapeutic radiology physician with a practice address in San Luis Obispo, California, and NPI 1598942781, issued on Jan 30, 2008. Check the license (California A121032, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Robert Ryn Johnson
- Credential
- M.D.
- Primary taxonomy
- Therapeutic Radiology Physician 2085R0203X
- License number
- A121032 CA
Self-reported in NPPES; status is on the state search - Practice location
- 100 Casa St Ste C, San Luis Obispo, CA 93405
- Phone
- (805) 541-1932
- Enumerated
- Jan 30, 2008
- Record last updated
- Oct 21, 2022
- Fax
- (805) 541-1653
- Medicaid ID
- 1598942781 CA
- Medicare enrollment
- Enrolled (PECOS I20120716000466); accepts Medicare assignment
- Medical or professional school
- Cincinnati College Of Medicine And Surgery, 2007
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest therapeutic radiology physician records → All 28 in California → Look up another NPI →
Also registered at 100 Casa St Ste C
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Jeffrey Wu, M.D.Radiation Oncology Physician1336331289
Verify Robert Ryn Johnson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A121032Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
54% fewer Medicare Part D claims than the average therapeutic radiology physician in 2024
74 Medicare Part D claims for 33 beneficiaries, against an average of 161 among the 108 providers of this specialty who prescribed in Part D. 21 claims were for opioids.
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.
The MIPS final score for 2023 (Medicare payment program): 79.1 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Sutter Bay Medical FoundationSan Luis Obispo, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Robert Ryn Johnson among 28 therapeutic radiology physician records in California
Robert Ryn Johnson, M.D. is one of 28 therapeutic radiology physician records with a practice address in California. 32% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2008, is newer than 75% of them.
- NPI issued2008 · 75% of these records are older, 18% newer
- In a Medicare fileYes · 32% of these records are
- In the CMS Doctors and Clinicians fileYes · 29% of these records are
- Record last updated2022 · 79% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0203X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Therapeutic Radiology Physician providers in California
There are 28 therapeutic radiology physician records in California.
All 28 in California → Every provider in San Luis Obispo → Therapeutic Radiology Physician nationwide →
The 8 therapeutic radiology physician records with the nearest ZIP codes
- Owen Kim, M.D.Porterville, CA 932571861574352
- Patrick Welton, MDCarmel, CA 939211427644798
- Nilam S Ramsinghani, MDOrange, CA 928681043390289
- Neena P Shah, MDOrange, CA 928681700954021
- Pauling Chang, MDSunnyvale, CA 940861194884692
- Richard Krieg, MDSan Francisco, CA 941151124062351
- Bryan Leigh, M.D.San Clemente, CA 926731407272669
- Jay Tassin, M.D.San Clemente, CA 926731659787596
Common questions
What is Robert Ryn Johnson, M.D.'s NPI number?
Robert Ryn Johnson, M.D.'s National Provider Identifier (NPI) is 1598942781, issued on Jan 30, 2008. An NPI identifies a provider in billing; it is not a license.
Where is Robert Ryn Johnson, M.D. located?
The NPPES record lists a practice address at 100 Casa St Ste C, San Luis Obispo, CA, 93405. Phone: (805) 541-1932. Providers update this record themselves, so call before visiting.
How can I verify Robert Ryn Johnson, M.D.'s license?
NPPES lists California license number A121032, 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 Robert Ryn Johnson, M.D. prescribe under Medicare Part D?
In 2024, Robert Ryn Johnson, M.D. had 74 Medicare Part D claims for 33 beneficiaries; the average among therapeutic radiology physician prescribers was 161. Part D covers Medicare prescriptions only.
What is Robert Ryn Johnson, M.D.'s MIPS final score?
The 2023 MIPS final score is 79.1 of 100. The average among 454,083 clinicians with a measured score was 83.5.
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.