Quick answers
- Does Holly S. Mason accept Medicare assignment?
- Yes. Medicare's clinician data says Holly S. Mason 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 Holly S. Mason see?
- In 2024, CMS data shows 93 Original Medicare patients and 230 services for Holly S. Mason. This counts Original Medicare only and measures volume, not quality.
- What is Holly S. Mason's NPI number?
- 1033201462. 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 Holly S. Mason, 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 | 93 |
|---|---|
| Services billed to Medicare | 230 |
| Different services or procedures | 26 |
| Participating Medicare provider | Yes |
| Average age of these patients | 72 |
Most frequent services
- Partial removal of breast (19301)32 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)32 services
- New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more (99205)28 services
- Imaging of lymph nodes during surgery (38900)22 services
- Biopsy or removal of deep lymph nodes of underarm (38525)20 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).
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)75%
- High cholesterol67%
- High blood pressure66%
- Arthritis45%
- Anxiety32%
- Depression27%
Hospitals where Holly S. Mason works
Medicare's Facility Affiliation Data lists Holly S. Mason 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.
- Baystate Franklin Medical CenterGreenfield, MA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 220016
- Baystate Medical CenterSpringfield, MA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 220077
- Baystate Noble HospitalWestfield, MA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 220065
Practice locations
Addresses where Holly S. Mason is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 6; the Medicare profile lists all.
- 100 Wason AveSpringfield, MA 01107
- 280 Chestnut St, Suite 2Springfield, MA 01199
- 3300 Main StSpringfield, MA 01107
- 3300 Main St, Fl 4Springfield, MA 01107 (413) 794‑7045
- 3350 Main StSpringfield, MA 01107 (413) 794‑9338
Group practices
Medicare enrollment lists Holly S. Mason as a member of this group (CMS data updated October 2, 2026).
- Baystate Medical Practices Inc1,369 clinicians in the group
Specialties
- Surgical Oncologyprimary
- General Surgeryalso
Other surgical oncologists in Springfield
Clinicians with the same Medicare primary specialty in Springfield, MA — not a recommendation.
Other clinicians in Baystate Medical Practices Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Vermont College Of Medicine |
| Graduation year | 1995 (31 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1033201462 |
| 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