Erin Ruiz, MD
Emergency Medicine Physician · Palo Alto, CA
Erin Ruiz, MD is an emergency medicine physician with a practice address in Palo Alto, California, and NPI 1881213478, issued on Apr 13, 2020. Check the license (California A187143, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Erin Ruiz
- Credential
- MD
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- A187143 CA
Self-reported in NPPES; status is on the state search - Practice location
- 900 Welch RD Ste 350, Palo Alto, CA 94304
- Phone
- (650) 723-9215
- Enumerated
- Apr 13, 2020
- Record last updated
- May 23, 2024
- Medicare enrollment
- Enrolled (PECOS I20240805003693); accepts Medicare assignment
- Medical or professional school
- Temple University School Of Medicine, 2020
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 7,751 in California → Look up another NPI →
Also registered at 900 Welch RD Ste 350
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Areeba Abid, MDStudent in an Organized Health Care Education/Training Program1982363941
- Dalton BrunsonStudent in an Organized Health Care Education/Training Program1730977281
- Claire CassianniStudent in an Organized Health Care Education/Training Program1538957063
- Brenda Castolo, AGACNP-BCNurse Practitioner1083195408
- Peter Davis-Allen, MDEmergency Medicine Physician1043839657
- Ursula Dean, BSN, RN, MSN, NPFamily Nurse Practitioner1063813350
Verify Erin Ruiz in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A187143Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
69% fewer Medicare Part D claims than the average emergency medicine physician in 2024
70 Medicare Part D claims for 57 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D. 11 claims were for opioids.
Most prescribed
- Cephalexin15 claims
- Oxycodone Hcl11 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.
Bills Medicare through one group practice
- Emergency Medicine Specialists OF Orange CountyOrange, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Erin Ruiz among 7,751 emergency medicine physician records in California
Erin Ruiz, MD is one of 7,751 emergency medicine 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 2020, is newer than 88% of them.
- NPI issued2020 · 88% of these records are older, 8% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 59% of these records are
- Graduated2020 · median 2011 among the 4,560 with a school on file
- Record last updated2024 · 59% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207P00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Emergency Medicine Physician providers in California
There are 7,751 emergency medicine physician records in California.
All 7,751 in California → Every provider in Palo Alto → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Terence Ahern, MDPalo Alto, CA 943041104195916
- Christopher Evans, D.O.Palo Alto, CA 943041902227788
- Tonia Fox, MDPalo Alto, CA 943041023050242
- William Johnston, M.D.Palo Alto, CA 943041417366584
- Derrick Lung, MDPalo Alto, CA 943041821259342
- Anne Merritt, M.D.Palo Alto, CA 943041730322967
- Robert Norris, M.D.Palo Alto, CA 943041124177928
- Sabrina Pak, MDPalo Alto, CA 943041548332018
Common questions
What is Erin Ruiz, MD's NPI number?
Erin Ruiz, MD's National Provider Identifier (NPI) is 1881213478, issued on Apr 13, 2020. An NPI identifies a provider in billing; it is not a license.
Where is Erin Ruiz, MD located?
The NPPES record lists a practice address at 900 Welch RD Ste 350, Palo Alto, CA, 94304. Phone: (650) 723-9215. Providers update this record themselves, so call before visiting.
How can I verify Erin Ruiz, MD's license?
NPPES lists California license number A187143, 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 Erin Ruiz, MD prescribe under Medicare Part D?
In 2024, Erin Ruiz, MD had 70 Medicare Part D claims for 57 beneficiaries; the average among emergency medicine physician prescribers was 226. 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.