Cathy Lynn Riker, MD
Rheumatology Physician · Menlo Park, CA
Cathy Lynn Riker, MD is a rheumatology physician with a practice address in Menlo Park, California, and NPI 1255448189, issued on Aug 24, 2006. Check the license (California G74920, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Cathy Lynn Riker
- Credential
- MD
- Primary taxonomy
- Rheumatology Physician 207RR0500X
- License number
- G74920 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1300 Crane St, Menlo Park, CA 94025
- Phone
- (650) 498-6500
- Enumerated
- Aug 24, 2006
- Record last updated
- Apr 16, 2024
- Medicare enrollment
- Enrolled (PECOS I20090212000260); accepts Medicare assignment
- Medical or professional school
- Icahn School Of Medicine At Mount Sinai, 1986
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest rheumatology physician records → All 926 in California → Look up another NPI →
Also registered at 1300 Crane St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Cathy Lynn Riker in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G74920Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
43% fewer Medicare Part D claims than the average rheumatology physician in 2024
1,122 Medicare Part D claims for 142 beneficiaries, against an average of 1,978 among the 6,301 providers of this specialty who prescribed in Part D.
Most prescribed
- Prednisone203 claims
- Hydroxychloroquine Sulfate172 claims
- Methotrexate98 claims
- Allopurinol76 claims
- Alendronate Sodium41 claims
- Cevimeline Hcl39 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.
Industry payments in 2024: $109.68
5 payments; by number, the most common kind was food and beverage; the largest payer was Novartis Pharmaceuticals Corporation. The 4,486 providers of this specialty with any payment received $8,538.33 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- University Healthcare AllianceMenlo Park, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Cathy Lynn Riker among 926 rheumatology physician records in California
Cathy Lynn Riker, MD is one of 926 rheumatology physician records with a practice address in California. 81% 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 6% of them.
- NPI issued2006 · 6% of these records are older, 55% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 69% of these records are
- Graduated1986 · median 2003 among the 641 with a school on file
- Record last updated2024 · 62% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RR0500X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Rheumatology Physician providers in California
There are 926 rheumatology physician records in California.
All 926 in California → Every provider in Menlo Park → Rheumatology Physician nationwide →
The 8 rheumatology physician records with the nearest ZIP codes
- Thomas Okarma, PH.D., M.D.Menlo Park, CA 940251972761492
- Amy Elliott, MDLos Altos, CA 940221124243092
- Vibeke Strand, M.D.Portola Valley, CA 940281194882753
- Zi Ying Li, M.DDaly City, CA 940151588160550
- Jeffrey Brown, MDMountain View, CA 940401750477758
- Herbert Fisher, M.D.Burlingame, CA 940101194829127
- Daniel Jo, M.D.Mountain View, CA 940401508150590
- Jennifer Johnson, M.D.Mountain View, CA 940401043582109
Common questions
What is Cathy Lynn Riker, MD's NPI number?
Cathy Lynn Riker, MD's National Provider Identifier (NPI) is 1255448189, issued on Aug 24, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Cathy Lynn Riker, MD located?
The NPPES record lists a practice address at 1300 Crane St, Menlo Park, CA, 94025. Phone: (650) 498-6500. Providers update this record themselves, so call before visiting.
How can I verify Cathy Lynn Riker, MD's license?
NPPES lists California license number G74920, 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 Cathy Lynn Riker, MD prescribe under Medicare Part D?
In 2024, Cathy Lynn Riker, MD had 1,122 Medicare Part D claims for 142 beneficiaries; the average among rheumatology physician prescribers was 1,978. 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.