Quick answers
- Does Dennis S. Oh accept Medicare assignment?
- Yes. Medicare's clinician data says Dennis S. Oh 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 Dennis S. Oh see?
- In 2024, CMS data shows 551 Original Medicare patients and 1,220 services for Dennis S. Oh. This counts Original Medicare only and measures volume, not quality.
- What is Dennis S. Oh's NPI number?
- 1225111511. 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 Dennis S. Oh, 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 | 551 |
|---|---|
| Services billed to Medicare | 1,220 |
| Different services or procedures | 36 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)308 services
- Insertion of cage or mesh device to spine bone and disc space during spine fusion (22853)173 services
- New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more (99205)118 services
- Partial removal of spine bone with release of lower spinal cord and/or nerves, 1 segment (63047)89 services
- Fusion of upper spine bone with removal of disc and release of spinal cord or nerve, 1 disc (22551)75 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).
- Arthritis75%
- High cholesterol74%
- High blood pressure73%
- Anxiety30%
- Diabetes24%
- Depression24%
Hospitals where Dennis S. Oh works
Medicare's Facility Affiliation Data lists Dennis S. Oh 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
- Fairview HospitalGreat Barrington, MA · Critical Access Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 221302
- The Cooley Dickinson Hospital IncNorthampton, MA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 220015
Practice locations
Addresses where Dennis S. Oh is enrolled with Medicare (CMS data updated October 2, 2026).
- 2 Medical Ctr DrSpringfield, MA 01107
- 2 Medical Ctr Dr, Suite 505 506Springfield, MA 01107 (413) 795‑1120
- 280 Chestnut St, Suite 2Springfield, MA 01199
- 759 Chestnut StSpringfield, MA 01199
Group practices
Medicare enrollment lists Dennis S. Oh as a member of this group (CMS data updated October 2, 2026).
- Baystate Medical Practices Inc1,369 clinicians in the group
Specialties
- Neurosurgeryprimary
Other neurosurgeons 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 |
|---|---|
| Graduation year | 1992 (34 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1225111511 |
| 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