Rex Chang, MD
NPI 1174143622 · Family Medicine Physician · El Segundo, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Rex Chang, MD is a Family Medicine Physician provider in El Segundo, CA (NPI 1174143622).
Provider details
- NPI number
- 1174143622
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A193710 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
6 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
108 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 45 | $137 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 41 | $99 |
| Administration of Influenza Virus VaccineG0008 | 11 | $35 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 11 | $141 |
Typical Medicare-allowed amounts for these services range $35–$141 (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 · 23 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 61 | 25 |
| Omeprazole | 49 | 16 |
| Lisinopril | 42 | 13 |
| Meloxicam | 35 | — |
| Duloxetine Hcl | 28 | — |
| Baclofen | 27 | — |
| Potassium Chloride | 27 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$229 across 11 records (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
Additional practice locations (1)
- 1414 W Fair Ave Ste 36Marquette, MI 49855-2675Phone: (906) 449-1010
Registry dates
- Enumerated
- 2020-04-24
- Last updated
- 2025-12-18
- Certified
- 2025-12-18
Frequently asked questions
- What is Rex Chang's NPI number?
- Rex Chang's National Provider Identifier (NPI) is 1174143622, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Rex Chang's specialty?
- Rex Chang is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Rex Chang located?
- Rex Chang's practice location on file with NPPES is 2110 E El Segundo Blvd, El Segundo, CA 90245-4548.
- What is Rex Chang's phone number?
- The practice phone number listed in the NPPES registry for Rex Chang is (310) 517-7010.
- Does Rex Chang accept Medicare?
- Rex Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Rex Chang's NPI active?
- Yes — Rex Chang's NPI (1174143622) is active in the NPPES registry as of the last update on 2025-12-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.