Aaron Thomas Byczynski
Internal Medicine · Milwaukee, WI
At a glance
945 N 12Th St, Milwaukee, WI 53233-1305
NPPES record updated Jul 24, 2026. Public records can lag behind changes at a practice.
Before you call: a quick checklist
- Are you accepting new patients?
- Do you accept my specific insurance plan?
- Do you provide the service I need at this address?
- Do I need a referral, and what is the earliest appointment?
Insurance participation and appointment availability are not established by these public records.
Medicare & insurance
Insurance participation is not established by these public records. Ask the practice and your insurer about your specific plan and this location.
How to check your coverage
Use your plan’s provider directory or the member-services number on your insurance card. Confirm the clinician, practice address, service, and whether a referral is required. A missing opt-out record does not establish Medicare acceptance.
Check the official Medicare directory ↗Practice location
945 N 12Th StMilwaukee, WI 53233-1305
Additional reported practice locations
8701 Watertown Plank RdMilwaukee, WI 532263548
Phone: 4149554575
Education & affiliations
- Medical / professional school
- West Virginia School Of Osteopathic Medicine
- Graduation year
- 2023
- CMS specialties
- Internal Medicine
Practice groups
Reported hospital affiliations
- Aurora St Lukes Medical Center Milwaukee, WI
Graduation year does not establish years in practice. A reported affiliation does not establish employment, current admitting privileges, or insurance participation.
Source: CMS National Downloadable File · Published Oct 15, 2026.
Source: CMS Facility Affiliation Data · Published Oct 15, 2026.
Procedures in the public data
Reported activity can help you ask more informed questions about a practice’s services.
No displayed procedure-category record in this release. This does not mean the clinician performs no procedures.
CMS uses a one-year claims window with a reporting lag. Counts cover the Medicare activity included by CMS, not all patients. “1–10” is a published range. Volume is not a quality or outcomes score. Coverage and methodology
Source: CMS Utilization Data · Published Oct 15, 2026.
Service-mix comparison is unavailable for this NPI in the imported Medicare service file.
Industry-reported general payments
No matching general-payment summary in the imported release. This is not a verified zero and does not rule out other payment types or years.
Source: CMS 2025 payments grouped by covered recipient and nature of payments · Published Jun 30, 2026.
Professional details: NPI, taxonomy & registry record
Registry details
- Primary taxonomy
- Internal Medicine
- Taxonomy code
- 207R00000X
- Enumeration date
- Mar 23, 2023
- Record updated
- Jul 24, 2026
More registry details
- Provider type
- Individual · Type 1
Reported taxonomies and licenses
207R00000X · Primary
License reported: 81699 WI
License numbers and credentials are reported to NPPES; HCPList does not independently verify them.
Practice location
945 N 12Th StMilwaukee, WI 53233-1305
- Phone
- (414) 219-2000
Mailing address
PO BOX 735044CHICAGO, IL 606735044
Information may be outdated or incomplete. Confirm details directly with the practice. HCPList is an independent directory and is not affiliated with CMS.
Report a directory issue