Katharine Marshall, MD
Katharine Marshall, MD is an Addiction Medicine (Internal Medicine) Physician in Portland, OR, registered under NPI 1891143327. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 3500 N INTERSTATE AVE, Portland, OR 97227. 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 |
|---|---|---|
| MD194144 | OR | Internal Medicine Physician |
| PG189357 | OR | Student in an Organized Health Care… |
| MD194144 | OR | Addiction Medicine (Internal Medicine)… primary |
This provider holds licence MD194144 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
- Practitioner - Internal Medicine
- PAC ID
- 0648563445
Enrolled in Medicare 2 times, across 2 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Oregon | I20190815000907 | Practitioner - Internal Medicine |
| Washington | I20221004001630 | Practitioner - Addiction Medicine |
Medicare enrolment is recorded as approved under the provider type Practitioner - Internal Medicine. There are 2 separate enrolment records across 2 states (OR, WA). Multiple enrolments usually mean the provider bills Medicare from more than one practice location, or has kept an earlier enrolment after moving. Each record carries its own enrolment ID, listed above. 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 Addiction Medicine covers
An internist doctor of osteopathy that specializes in the treatment of addiction disorders. A doctor of osteopathy that is board eligible/certified by the American Osteopathic Board of Internal Medicine can obtain a Certificate of Added Qualifications in the field of Addiction Medicine. NUCC Health Care Provider Taxonomy, code 207RA0401X
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 | |
|---|---|---|---|---|
| 207R00000X | Internal Medicine Physician | MD194144 | OR | |
| 390200000X | Student in an Organized Health Care Education/Training Program | PG189357 | OR | |
| 207RA0401X | Addiction Medicine (Internal Medicine) Physician Addiction Medicine | MD194144 | OR | 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 | 1891143327 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 25, 2016 |
| Last updated | Jan 14, 2026 |
| Status | Active |
| Sole proprietor | No |
| Gender | Female |
| Credential | MD |
| Practice address |
3500 N INTERSTATE AVE Portland, OR 97227 (800) 813-2000 |
| Mailing address |
500 NE MULTNOMAH ST STE 100 Portland, OR 97232 |
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 | 9 | 1 | 1 | 4 | 3 | 3 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 9 | 1 | 2 | 4 | 6 | 3 | 4 |
Sum = 63 · next multiple of 10 = 70 · 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.