Mark Chien, M.D.
NPI 1356374383 · Internal Medicine Physician · Chicago, IL
Mark Chien, M.D. is a Internal Medicine Physician provider in Chicago, IL (NPI 1356374383).
Provider details
- NPI number
- 1356374383
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
19 yrs in NPPES registry
- Profile completeness33% of score
83% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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 prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 51 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 122 | 42 |
| Amlodipine Besylate | 120 | 31 |
| Levothyroxine Sodium | 88 | 24 |
| Losartan Potassium | 82 | 22 |
| Metoprolol Succinate | 77 | 22 |
| Omeprazole | 53 | 16 |
| Hydrochlorothiazide |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$432 across 18 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
Registry dates
- Enumerated
- 2006-07-10
- Last updated
- 2007-07-08
Frequently asked questions
- What is Mark Chien's NPI number?
- Mark Chien's National Provider Identifier (NPI) is 1356374383, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Chien's specialty?
- Mark Chien is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Chien located?
- Mark Chien's practice location on file with NPPES is 680 N Lake Shore Dr, Chicago, IL 60611-4546.
- What is Mark Chien's phone number?
- The practice phone number listed in the NPPES registry for Mark Chien is (312) 503-6000.
- Is Mark Chien's NPI active?
- Yes — Mark Chien's NPI (1356374383) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.