Chang-Gyu Hahn, MD
NPI 1558472100 · Psychiatry Physician · Philadelphia, PA
Enrolled with Medicare as Practitioner - Psychiatry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Chang-Gyu Hahn, MD is a Psychiatry Physician provider in Philadelphia, PA (NPI 1558472100).
Provider details
- NPI number
- 1558472100
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- MD048469L (PA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
74 Medicare services, 2024 (ranked within specialty)
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 methodology.
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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 74 | $130 |
Typical Medicare-allowed amounts for these services range $130–$130 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 20 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Clonazepam | 86 | 14 |
| Aripiprazole | 50 | — |
| Quetiapine Fumarate | 48 | — |
| Escitalopram Oxalate | 46 | — |
| Trazodone Hcl | 42 | — |
| Clozapine | 39 | — |
| Olanzapine | 36 | — |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-08-31
- Last updated
- 2011-02-18
Frequently asked questions
- What is Chang-Gyu Hahn's NPI number?
- Chang-Gyu Hahn's National Provider Identifier (NPI) is 1558472100, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Chang-Gyu Hahn's specialty?
- Chang-Gyu Hahn is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is Chang-Gyu Hahn located?
- Chang-Gyu Hahn's practice location on file with NPPES is 3535 Market St, Philadelphia, PA 19104-3309.
- What is Chang-Gyu Hahn's phone number?
- The practice phone number listed in the NPPES registry for Chang-Gyu Hahn is (215) 746-6700.
- Does Chang-Gyu Hahn accept Medicare?
- Chang-Gyu Hahn is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Chang-Gyu Hahn's NPI active?
- Yes — Chang-Gyu Hahn's NPI (1558472100) is active in the NPPES registry as of the last update on 2011-02-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.