Jonathan Ernst, MD
Jonathan Ernst, MD is a Family Medicine Physician in Madison, WI, registered under NPI 1548675697. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 1211 FISH HATCHERY RD, Madison, WI 53715. 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 |
|---|---|---|
| 67864-20 | WI | Family Medicine Physician primary |
| 67864-20 | WI | Internal Medicine Physician |
| 67864-20 | WI | Pediatrics Physician |
This provider holds licence 67864-20 issued in WI. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Family Practice
- PAC ID
- 0840503637
- Enrollment ID
- I20171113000919
Medicare enrolment is recorded as approved under the provider type Practitioner - Family Practice. 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.
What Family Medicine covers
Family Medicine is the medical specialty which is concerned with the total health care of the individual and the family. It is the specialty in breadth which integrates the biological, clinical, and behavioral sciences. The scope of family medicine is not limited by age, sex, organ system, or disease entity. NUCC Health Care Provider Taxonomy, code 207Q00000X
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 | |
|---|---|---|---|---|
| 207Q00000X | Family Medicine Physician | 67864-20 | WI | primary |
| 207R00000X | Internal Medicine Physician | 67864-20 | WI | |
| 208000000X | Pediatrics Physician | 67864-20 | WI |
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 | 1548675697 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 27, 2014 |
| Last updated | May 24, 2022 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
1211 FISH HATCHERY RD Madison, WI 53715 (608) 252-8000 Fax (608) 283-7160 |
| Other identifiers |
1548675697
· 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 | 4 | 8 | 6 | 7 | 5 | 6 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 8 | 8 | 3 | 7 | 1 | 6 | 9 |
Sum = 73 · next multiple of 10 = 80 · check digit = 7 · actual last digit = 7
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.