Derek Fong, MD
Derek Fong, MD is a Gastroenterology Physician in Harbor City, CA, registered under NPI 1497876247.
Getting there
The practice address on file is 25825 VERMONT AVE DEPARTMENT OF GASTROENTEROLOGY, Harbor City, CA 90710. 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 |
|---|---|---|
| A77880 | CA | Gastroenterology Physician primary |
| 222058 | MA | Gastroenterology Physician |
Licences are recorded in 2 states: CA, MA. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Gastroenterology
- PAC ID
- 6103721477
Medicare enrolment is recorded as approved under the provider type Practitioner - Gastroenterology. This means the provider is enrolled to bill Medicare, though 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: California and Massachusetts. The practice address on file is in Harbor City, CA, 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
- A77880
- Specialty
- Gastroenterology 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 Gastroenterology covers
An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs. NUCC Health Care Provider Taxonomy, code 207RG0100X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207RG0100X | Gastroenterology Physician Gastroenterology | A77880 | CA | primary |
| 207RG0100X | Gastroenterology Physician Gastroenterology | 222058 | MA |
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 | 1497876247 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 2, 2007 |
| Last updated | Nov 18, 2021 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
25825 VERMONT AVE DEPARTMENT OF GASTROENTEROLOGY Harbor City, CA 90710 (800) 780-1230 |
| Mailing address |
5958 OCEAN TERRACE DR Rancho Palos Verdes, CA 90275 |
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 | 4 | 9 | 7 | 8 | 7 | 6 | 2 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 9 | 7 | 7 | 7 | 3 | 2 | 8 |
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.