Mark Hwang
NPI 1487049037 · Radiation Oncology Physician · Greenwich, CT
Enrolled with Medicare as Practitioner - Radiation Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Hwang is a Radiation Oncology Physician provider in Greenwich, CT (NPI 1487049037).
Provider details
- NPI number
- 1487049037
- Entity type
- Individual
- Primary specialty
- Radiation Oncology PhysicianAllopathic & Osteopathic Physicians
- Sex
- Male
- Sole proprietor
- No
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
11 yrs in NPPES registry
- Profile completeness25% of score
83% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
2,243 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Ct Guidance for Insertion of Radiation Therapy Fields77014 | 813 | $42 |
| Ct Guidance for Insertion of Radiation Therapy Fields77014 | 326 | $42 |
| Calculation of Radiation Therapy Dose77300 | 136 | $31 |
| Radiation Treatment Management, 5 Treatment Sessions77427 | 126 | $178 |
| Radiation Treatment Management, 5 Treatment Sessions77427 | 105 | $177 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 97 | $61 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 8 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Tamsulosin Hcl | 671 | 197 |
| Oxybutynin Chloridebrand: Oxybutynin Chloride Er | 154 | 41 |
| Megestrol Acetate | 85 | 26 |
| Methylprednisolone | 59 | 37 |
| Alfuzosin Hclbrand: Alfuzosin Hcl Er | 20 | — |
| Ondansetronbrand: Ondansetron Odt | 18 | — |
| Dexamethasone | 12 | 11 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$20 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2015-03-31
- Last updated
- 2020-11-18
- Certified
- 2020-11-18
Frequently asked questions
- What is Mark Hwang's NPI number?
- Mark Hwang's National Provider Identifier (NPI) is 1487049037, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Hwang's specialty?
- Mark Hwang is listed in the NPPES registry with a primary specialty of Radiation Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Hwang located?
- Mark Hwang's practice location on file with NPPES is 5 Perryridge Rd, Greenwich, CT 06830-4608.
- What is Mark Hwang's phone number?
- The practice phone number listed in the NPPES registry for Mark Hwang is (208) 863-3911.
- Does Mark Hwang accept Medicare?
- Mark Hwang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Hwang's NPI active?
- Yes — Mark Hwang's NPI (1487049037) is active in the NPPES registry as of the last update on 2020-11-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.