Stephen Brennan, MD
NPI 1588168025 · Psychiatry Physician · Oconomowoc, WI
Enrolled with Medicare as Practitioner - Psychiatry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Stephen Brennan, MD is a Psychiatry Physician provider in Oconomowoc, WI (NPI 1588168025).
Provider details
- NPI number
- 1588168025
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- 81856 (IA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
8 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
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 · 1 distinct drug on file.
| Drug | Part D claims (2024) |
|---|---|
| Trazodone Hcl | 12 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2018-03-20
- Last updated
- 2024-01-11
- Certified
- 2024-01-11
Frequently asked questions
- What is Stephen Brennan's NPI number?
- Stephen Brennan's National Provider Identifier (NPI) is 1588168025, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Stephen Brennan's specialty?
- Stephen Brennan is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is Stephen Brennan located?
- Stephen Brennan's practice location on file with NPPES is 1230 Corporate Center Dr Ste 400, Oconomowoc, WI 53066-4883.
- What is Stephen Brennan's phone number?
- The practice phone number listed in the NPPES registry for Stephen Brennan is (262) 646-6311.
- Does Stephen Brennan accept Medicare?
- Stephen Brennan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Stephen Brennan's NPI active?
- Yes — Stephen Brennan's NPI (1588168025) is active in the NPPES registry as of the last update on 2024-01-11.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.