John Ernzen, MD
NPI 1346615663 · Psychiatry Physician · Chicago, IL
Enrolled with Medicare as Practitioner - Psychiatry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Ernzen, MD is a Psychiatry Physician provider in Chicago, IL (NPI 1346615663).
Provider details
- NPI number
- 1346615663
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
10 yrs in NPPES registry
- Profile completeness28% of score
83% of core fields populated
- Practice footprint17% of score
4 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
95 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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 84 | $81 |
| Psychiatric Diagnostic Evaluation With Medical Services90792 | 11 | $173 |
Typical Medicare-allowed amounts for these services range $81–$173 (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.
Practice location
Mailing address
Additional practice locations (3)
- 240 E Huron StSuite 1-200Chicago, IL 60611-2909Phone: (312) 503-7975
- 1740 W Taylor StChicago, IL 60612-7232Phone: (866) 600-2273
- 2650 Ridge Ave.Department of PsychiatryEvanston, IL 60201-1718Phone: (847) 570-2540Fax: (847) 570-2939
Registry dates
- Enumerated
- 2015-12-11
- Last updated
- 2022-05-27
- Certified
- 2022-05-12
Frequently asked questions
- What is John Ernzen's NPI number?
- John Ernzen's National Provider Identifier (NPI) is 1346615663, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Ernzen's specialty?
- John Ernzen is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is John Ernzen located?
- John Ernzen's practice location on file with NPPES is 225 E Chicago Ave, Chicago, IL 60611-2991.
- What is John Ernzen's phone number?
- The practice phone number listed in the NPPES registry for John Ernzen is (312) 227-4000.
- Does John Ernzen accept Medicare?
- John Ernzen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Ernzen's NPI active?
- Yes — John Ernzen's NPI (1346615663) is active in the NPPES registry as of the last update on 2022-05-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.