Nancy Tsai, M.D.
Nancy Tsai, M.D. is a Neonatal-Perinatal Medicine Physician in Green Bay, WI, registered under NPI 1528277225. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 2845 GREENBRIER RD, Green Bay, WI 54311. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 238495 | MA | Pediatrics Physician |
| MD12613 | RI | Pediatrics Physician |
| 55710-20 | WI | Neonatal-Perinatal Medicine Physician primary |
Licences are recorded in 3 states: MA, RI, WI. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Pediatric Medicine
- PAC ID
- 5395064430
- Enrollment ID
- I20150512001003
Medicare enrolment is recorded as approved under the provider type Practitioner - Pediatric Medicine. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
Licensed in 3 states
This provider holds licences in 3 states: Massachusetts, Rhode Island and Wisconsin. The practice address on file is in Green Bay, WI, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
- Licence
- 55710-20
- Specialty
- Neonatal-Perinatal Medicine Physician
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Neonatal-Perinatal Medicine covers
A pediatrician who is the principal care provider for sick newborn infants. Clinical expertise is used for direct patient care and for consulting with obstetrical colleagues to plan for the care of mothers who have high-risk pregnancies. NUCC Health Care Provider Taxonomy, code 2080N0001X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 208000000X | Pediatrics Physician | 238495 | MA | |
| 208000000X | Pediatrics Physician | MD12613 | RI | |
| 2080N0001X | Neonatal-Perinatal Medicine Physician Neonatal-Perinatal Medicine | 55710-20 | WI | primary |
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1528277225 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 21, 2007 |
| Last updated | Jun 25, 2025 |
| Status | Active |
| Sole proprietor | No |
| Gender | Female |
| Credential | M.D. |
| Practice address |
2845 GREENBRIER RD Green Bay, WI 54311 (920) 288-4560 Fax (920) 288-4558 |
| Mailing address |
PO BOX 735044 Chicago, IL 60673 |
| Other identifiers |
100016094
· Medicaid (WI) |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 5 | 2 | 8 | 2 | 7 | 7 | 2 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 4 | 8 | 4 | 7 | 5 | 2 | 4 |
Sum = 65 · next multiple of 10 = 70 · check digit = 5 · actual last digit = 5
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.