Tony Chang, MD
NPI 1831166990 · Internal Medicine Physician · Madison, WI
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Tony Chang, MD is a Internal Medicine Physician provider in Madison, WI (NPI 1831166990).
Provider details
- NPI number
- 1831166990
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 42048 (WI)
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
20 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
1,000 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) |
|---|---|---|
| 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 | 293 | $15 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 242 | $9 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 160 | $120 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 103 | $85 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 87 | $167 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 134 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 565 | 122 |
| Amlodipine Besylate | 358 | 86 |
| Lisinopril | 295 | 76 |
| Apixabanbrand: Eliquis | 264 | 48 |
| Omeprazole | 218 | 48 |
| Losartan Potassium | 214 | 49 |
| Simvastatin |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-03-07
- Last updated
- 2021-01-04
- Certified
- 2021-01-04
Frequently asked questions
- What is Tony Chang's NPI number?
- Tony Chang's National Provider Identifier (NPI) is 1831166990, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Tony Chang's specialty?
- Tony Chang is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Tony Chang located?
- Tony Chang's practice location on file with NPPES is 20 S Park St, Madison, WI 53715.
- What is Tony Chang's phone number?
- The practice phone number listed in the NPPES registry for Tony Chang is (608) 287-2440.
- Does Tony Chang accept Medicare?
- Tony Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Tony Chang's NPI active?
- Yes — Tony Chang's NPI (1831166990) is active in the NPPES registry as of the last update on 2021-01-04.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.