Quick answers
- Does Shannon Gaffney accept Medicare assignment?
- Yes. Medicare's clinician data says Shannon Gaffney accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Shannon Gaffney see?
- In 2024, CMS data shows 2,337 Original Medicare patients and 5,023 services for Shannon Gaffney. This counts Original Medicare only and measures volume, not quality.
- What is Shannon Gaffney's NPI number?
- 1548459340. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Shannon Gaffney, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 2,337 |
|---|---|
| Services billed to Medicare | 5,023 |
| Different services or procedures | 90 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Screening mammography (77067)1,417 services
- Screening 3d breast mammography (77063)1,409 services
- Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066) (G0279)353 services
- X-ray of chest, 1 view (71045)244 services
- Diagnostic mammography of 1 breast (77065)235 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol75%
- High blood pressure67%
- Arthritis43%
- Osteoporosis33%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)24%
- Diabetes23%
Hospitals where Shannon Gaffney works
Medicare's Facility Affiliation Data lists Shannon Gaffney at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- John Muir Medical Center - Concord CampusConcord, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050496
- John Muir Medical Center - Walnut Creek CampusWalnut Creek, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 050180
- Stanford Health CareStanford, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050441
- Stanford Health Care Tri-ValleyPleasanton, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050283
Practice locations
Addresses where Shannon Gaffney is enrolled with Medicare (CMS data updated October 2, 2026).
- 1200 B Gale Wilson BlvdFairfield, CA 94533 (707) 646‑5000
- 1601 Ygnacio Valley RdWalnut Creek, CA 94598 (925) 295‑1545
- 2400 Balfour RdBrentwood, CA 94513 (925) 516‑3350
- 300 Pasteur DrStanford, CA 94305 (650) 723‑4000
Group practices
Medicare enrollment lists Shannon Gaffney as a member of these groups (CMS data updated October 2, 2026).
- Stanford Health Care3,122 clinicians in the group
- Bay Imaging Consultants Medical Group Inc146 clinicians in the group
- John Muir Magnetic Imaging Center57 clinicians in the group
Specialties
- Diagnostic Radiologyprimary
Other radiologists in Fairfield
Clinicians with the same Medicare primary specialty in Fairfield, CA — not a recommendation.
Other clinicians in Stanford Health Care
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | New York College Of Osteo Medicine Of New York Institute Of Technology |
| Graduation year | 2006 (20 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1548459340 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians