Quick answers
- Does Mahmoud B. El-Tamer accept Medicare assignment?
- Yes. Medicare's clinician data says Mahmoud B. El-Tamer 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 Mahmoud B. El-Tamer see?
- In 2024, CMS data shows 94 Original Medicare patients and 238 services for Mahmoud B. El-Tamer. This counts Original Medicare only and measures volume, not quality.
- What is Mahmoud B. El-Tamer's NPI number?
- 1235201856. 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 Mahmoud B. El-Tamer, 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 | 94 |
|---|---|
| Services billed to Medicare | 238 |
| Different services or procedures | 18 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more (99205)51 services
- Partial removal of breast (19301)33 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)31 services
- Imaging of lymph nodes during surgery (38900)23 services
- Biopsy or removal of deep lymph nodes of underarm (38525)22 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%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)75%
- High blood pressure68%
- Arthritis56%
- Diabetes29%
- Anxiety28%
Practice locations
Addresses where Mahmoud B. El-Tamer is enrolled with Medicare (CMS data updated October 2, 2026).
- 1133 York AveNew York, NY 10065 (646) 888‑7100
- 1275 York AveNew York, NY 10065 (212) 639‑2000
- 300 E 66th StNew York, NY 10065 (646) 888‑5200
Group practices
Medicare enrollment lists Mahmoud B. El-Tamer as a member of this group (CMS data updated October 2, 2026).
- MSKCC Surgery Group369 clinicians in the group
Specialties
- General Surgeryprimary
- Surgical Oncologyalso
Other general surgeons in New York
Clinicians with the same Medicare primary specialty in New York, NY — not a recommendation.
Other clinicians in MSKCC Surgery Group
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1981 (45 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1235201856 |
| 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
- 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