Ian Chang, D.O.
NPI 1407116411 · Rheumatology Physician · Orange, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Ian Chang, D.O. is a Rheumatology Physician provider in Orange, CA (NPI 1407116411).
Provider details
- NPI number
- 1407116411
- Entity type
- Individual
- Primary specialty
- Rheumatology PhysicianAllopathic & Osteopathic Physicians
- Credential
- D.O.
- Sex
- Male
- Sole proprietor
- No
- License
- 5101019682 (MI)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
14 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
190 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 High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 86 | $159 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 71 | $172 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More99205 | 19 | $232 |
| Visit Complexity Inherent to Evaluation and Management Associated With Medical Care Services That Serve As the Continuing Focal Point for All Needed Health Care Services And/Or With Medical Care Services That Are Part of Ongoing Care Related to a Patient'SG2211 | 14 | $18 |
Typical Medicare-allowed amounts for these services range $18–$232 (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 · 12 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Diclofenac Sodium | 38 | 18 |
| Adalimumabbrand: Humira(cf) Pen | 36 | — |
| Methotrexate Sodiumbrand: Methotrexate | 35 | — |
| Prednisone | 35 | 12 |
| Leflunomide | 26 | — |
| Gabapentin | 21 | — |
| Hydroxychloroquine Sulfate | 21 |
Practice location
Mailing address
Additional practice locations (1)
- 804 Service RoadRoom A225 Msu Clinical CenterEast Lansing, MI 48824Phone: (517) 353-4941Fax: (517) 432-3145
Registry dates
- Enumerated
- 2012-05-23
- Last updated
- 2023-03-29
- Certified
- 2023-03-29
Frequently asked questions
- What is Ian Chang's NPI number?
- Ian Chang's National Provider Identifier (NPI) is 1407116411, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Ian Chang's specialty?
- Ian Chang is listed in the NPPES registry with a primary specialty of Rheumatology Physician (Allopathic & Osteopathic Physicians).
- Where is Ian Chang located?
- Ian Chang's practice location on file with NPPES is 101 the City Dr S Bldg 30, Orange, CA 92868-3201.
- What is Ian Chang's phone number?
- The practice phone number listed in the NPPES registry for Ian Chang is (714) 456-7720.
- Does Ian Chang accept Medicare?
- Ian Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Ian Chang's NPI active?
- Yes — Ian Chang's NPI (1407116411) is active in the NPPES registry as of the last update on 2023-03-29.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.