Matthew Middendorf, MD
Matthew Middendorf, MD is an Internal Medicine Physician in Agana Heights, GU, registered under NPI 1629305784. 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 FARENHOLT AVE. BLDG. 50, Agana Heights, GU 96910. 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 |
|---|---|---|
| MD39270 | SC | Internal Medicine Physician primary |
| M-2396 | GU | Pulmonary Disease Physician |
| MD-P-2025-007 | GU | Pulmonary Disease Physician |
| MD39270 | SC | Pulmonary Disease Physician |
| M-2396 | GU | Critical Care Medicine (Internal… |
| MD-P-2025-007 | GU | Critical Care Medicine (Internal… |
| MD39270 | SC | Critical Care Medicine (Internal… |
Licences are recorded in 2 states: SC, GU. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Pulmonary Disease
- PAC ID
- 5698024750
- Enrollment ID
- I20231020000660
Medicare enrolment is recorded as approved under the provider type Practitioner - Pulmonary Disease. 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 2 states
This provider holds licences in 2 states: Guam and South Carolina. The practice address on file is in Agana Heights, GU, 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
- M-2396
- Specialty
- Pulmonary Disease 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 Internal Medicine covers
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs. NUCC Health Care Provider Taxonomy, code 207R00000X
All registered taxonomy codes
This provider registers 7 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 | MD39270 | SC | primary |
| 207RP1001X | Pulmonary Disease Physician Pulmonary Disease | M-2396 | GU | |
| 207RP1001X | Pulmonary Disease Physician Pulmonary Disease | MD-P-2025-007 | GU | |
| 207RP1001X | Pulmonary Disease Physician Pulmonary Disease | MD39270 | SC | |
| 207RC0200X | Critical Care Medicine (Internal Medicine) Physician Critical Care Medicine | M-2396 | GU | |
| 207RC0200X | Critical Care Medicine (Internal Medicine) Physician Critical Care Medicine | MD-P-2025-007 | GU | |
| 207RC0200X | Critical Care Medicine (Internal Medicine) Physician Critical Care Medicine | MD39270 | SC |
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 | 1629305784 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 11, 2009 |
| Last updated | Oct 1, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Male |
| Credential | MD |
| Practice address |
FARENHOLT AVE. BLDG. 50 Agana Heights, GU 96910 (671) 344-9340 |
| Mailing address |
PSC 455 BOX 208 Fpo, AP 96540 |
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 | 6 | 2 | 9 | 3 | 0 | 5 | 7 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 4 | 9 | 6 | 0 | 1 | 7 | 7 |
Sum = 66 · next multiple of 10 = 70 · check digit = 4 · actual last digit = 4
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.