Nathan Stumpf, MD
Nathan Stumpf, MD is a Geriatric Medicine (Internal Medicine) Physician in Portland, OR, registered under NPI 1881337269.
Getting there
The practice address on file is 500 NE MULTNOMAH ST STE 100, Portland, OR 97232. 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 |
|---|---|---|
| PG226671 | OR | Geriatric Medicine (Internal Medicine)… primary |
This provider holds licence PG226671 issued in OR. 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
- Order And Referring Only - Internal Medicine
- PAC ID
- 1456730225
- Enrollment ID
- I20220624001241
Medicare enrolment is recorded as approved under the provider type Order And Referring Only - Internal 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.
What Geriatric Medicine covers
An internist who has special knowledge of the aging process and special skills in the diagnostic, therapeutic, preventive and rehabilitative aspects of illness in the elderly. This specialist cares for geriatric patients in the patient's home, the office, long-term care settings such as nursing homes and the hospital. NUCC Health Care Provider Taxonomy, code 207RG0300X
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 | 1881337269 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 14, 2022 |
| Last updated | Aug 5, 2026 |
| Status | Active |
| Sole proprietor | No |
| Gender | Male |
| Credential | MD |
| Practice address |
500 NE MULTNOMAH ST STE 100 Portland, OR 97232 (360) 571-3005 |
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 | 8 | 8 | 1 | 3 | 3 | 7 | 2 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 7 | 1 | 6 | 3 | 5 | 2 | 3 |
Sum = 61 · next multiple of 10 = 70 · check digit = 9 · actual last digit = 9
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.