Quick answers
- Does Gregory J. Castiglia accept Medicare assignment?
- Yes. Medicare's clinician data says Gregory J. Castiglia 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 Gregory J. Castiglia see?
- In 2024, CMS data shows 170 Original Medicare patients and 1,841 services for Gregory J. Castiglia. This counts Original Medicare only and measures volume, not quality.
- What is Gregory J. Castiglia's NPI number?
- 1003891896. 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 Gregory J. Castiglia, 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 | 170 |
|---|---|
| Services billed to Medicare | 1,841 |
| Different services or procedures | 51 |
| Participating Medicare provider | Yes |
| Average age of these patients | 72 |
Most frequent services
- Injection, methylprednisolone acetate, 1 mg (J1010)1,486 services
- Injection of substance into lower spine canal using imaging guidance (62323)62 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)53 services
- New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more (99203)39 services
- Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes (99222)31 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 blood pressure75%
- High cholesterol75%
- Arthritis75%
- Anxiety45%
- Depression41%
- Chronic kidney disease35%
Hospitals where Gregory J. Castiglia works
Medicare's Facility Affiliation Data lists Gregory J. Castiglia 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.
- Erie County Medical CenterBuffalo, NY · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 330219
- Kenmore Mercy HospitalKenmore, NY · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 330102
- Mercy Hospital of BuffaloBuffalo, NY · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 330279
- Mount St. Mary's Hospital & Health CenterLewiston, NY · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 330188
- Sisters of Charity HospitalBuffalo, NY · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 330078
Practice locations
Addresses where Gregory J. Castiglia is enrolled with Medicare (CMS data updated October 2, 2026).
- 100 High StBuffalo, NY 14203 (716) 859‑3460
- 40 George Karl Blvd, Suite 200Amherst, NY 14221 (716) 218‑1000
- 40 George Karl Blvd, Suite 200Williamsville, NY 14221
- 5959 Big Tree RdOrchard Park, NY 14127 (716) 218‑1000
Group practices
Medicare enrollment lists Gregory J. Castiglia as a member of this group (CMS data updated October 2, 2026).
- University at Buffalo Neurosurgery Inc71 clinicians in the group
Specialties
- Neurosurgeryprimary
Other neurosurgeons in Buffalo
Clinicians with the same Medicare primary specialty in Buffalo, NY — not a recommendation.
Other clinicians in University at Buffalo Neurosurgery Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Columbia University College Of Physicians And Surgeons |
| 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) | 1003891896 |
| 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