Erin Elizabeth Farrelly, M.D., M.S.
Orthopaedic Surgery Physician · San Marcos, CA
Erin Elizabeth Farrelly, M.D., M.S. is an orthopaedic surgery physician with a practice address in San Marcos, California, and NPI 1922354422, issued on Aug 2, 2012. Check the license (California A121731, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Erin Elizabeth Farrelly
- Credential
- M.D., M.S.
- Primary taxonomy
- Orthopaedic Surgery Physician 207X00000X
- License number
- A121731 CA
Self-reported in NPPES; status is on the state search - Practice location
- 277 Rancheros Dr Ste 101, San Marcos, CA 92069
- Phone
- (760) 750-1902
- Enumerated
- Aug 2, 2012
- Record last updated
- Jan 6, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (760) 750-1906
- Medicare enrollment
- Enrolled (PECOS I20251210001998); accepts Medicare assignment
- Medical or professional school
- George Washington University School Of Medicine, 2007
- Entity
- Type 1 · individual
8 nearest orthopaedic surgery physician records → All 2,276 in California → Look up another NPI →
Also registered at 277 Rancheros Dr Ste 101
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Brooke Ballard, M.D.Orthopaedic Surgery Physician1841447950
- Michael Hachadorian, MDOrthopaedic Surgery Physician1740844836
- Hannah Kirby, M.D.Orthopaedic Surgery Physician1255671574
- Anisa Yalom, MDSurgery of the Hand (Surgery) Physician1164679908
Verify Erin Elizabeth Farrelly in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A121731Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
90% fewer Medicare Part D claims than the average orthopaedic surgery physician in 2024
36 Medicare Part D claims for 14 beneficiaries, against an average of 346 among the 16,516 providers of this specialty who prescribed in Part D.
Most prescribed
- Alendronate Sodium12 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 83.6 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. 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, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $1,212.10
8 payments; by number, the most common kind was food and beverage; the largest payer was Smith+Nephew, Inc. The 15,003 providers of this specialty with any payment received $23,022.89 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
- Medstar Medical Group II LLCWashington, DC
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Erin Elizabeth Farrelly among 2,276 orthopaedic surgery physician records in California
Erin Elizabeth Farrelly, M.D., M.S. is one of 2,276 orthopaedic surgery physician records with a practice address in California. 74% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2012, is newer than 77% of them.
- NPI issued2012 · 77% of these records are older, 20% newer
- In a Medicare fileYes · 74% of these records are
- In the CMS Doctors and Clinicians fileYes · 59% of these records are
- Graduated2007 · median 2003 among the 1,347 with a school on file
- Record last updated2021 · 66% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207X00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Orthopaedic Surgery Physician providers in California
There are 2,276 orthopaedic surgery physician records in California.
All 2,276 in California → Every provider in San Marcos → Orthopaedic Surgery Physician nationwide →
The 8 orthopaedic surgery physician records with the nearest ZIP codes
- Brooke Ballard, M.D.San Marcos, CA 920691841447950
- Michael Hachadorian, MDSan Marcos, CA 920691740844836
- Hannah Kirby, M.D.San Marcos, CA 920691255671574
- Philip Balikian, M.D.Poway, CA 920641407803687
- Philip Bohart, M.DPoway, CA 920641033223425
- James Bried, M.D.Poway, CA 920641891809257
- Brad Cohen, M.D.Poway, CA 920641164536538
- James Marino, M.D.Poway, CA 920641033293840
Common questions
What is Erin Elizabeth Farrelly, M.D., M.S.'s NPI number?
Erin Elizabeth Farrelly, M.D., M.S.'s National Provider Identifier (NPI) is 1922354422, issued on Aug 2, 2012. An NPI identifies a provider in billing; it is not a license.
Where is Erin Elizabeth Farrelly, M.D., M.S. located?
The NPPES record lists a practice address at 277 Rancheros Dr Ste 101, San Marcos, CA, 92069. Phone: (760) 750-1902. Providers update this record themselves, so call before visiting.
How can I verify Erin Elizabeth Farrelly, M.D., M.S.'s license?
NPPES lists California license number A121731, 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 Elizabeth Farrelly, M.D., M.S. prescribe under Medicare Part D?
In 2024, Erin Elizabeth Farrelly, M.D., M.S. had 36 Medicare Part D claims for 14 beneficiaries; the average among orthopaedic surgery physician prescribers was 346. Part D covers Medicare prescriptions only.
What is Erin Elizabeth Farrelly, M.D., M.S.'s MIPS final score?
The 2023 MIPS final score is 83.6 of 100, reported for the practice group. 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.