Oluwaseyi Balasire, M.D.
Oluwaseyi Balasire, M.D. is a Hospitalist Physician in Castro Valley, CA, registered under NPI 1003235243. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
Here is what surrounds this office in Castro Valley, based on OpenStreetMap data collected Sep 13, 2026. Parking is available about 0.48 mi away at John Drive Park and Ride. The nearest transit stop is 1,025 ft away, served by Somerset Avenue & Sprague Court. If you arrive early, there is a coffee shop 0.45 mi away.
Getting here and what is nearby
Parking 415 ft ~2 min
Transit Eden Medical Center 646 ft ~3 min
Transit Eden Medical Center 709 ft ~3 min
Transit Somerset Avenue & Sprague Court 1,025 ft ~4 min
Coffee Starbucks 0.28 mi ~6 min
2720 Castro Valley Boulevard, Castro Valley 94546
Gas station Stop n Save 0.29 mi ~6 min
20570 Stanton Avenue
Hotel Comfort Inn 0.30 mi ~6 min
2532 Castro Valley Boulevard, Castro Valley 94546
Gas station Arco 0.31 mi ~7 min
2770 Castro Valley Boulevard
Gas station Arco 0.31 mi ~7 min
2770 Castro Valley Boulevard
Restaurant Togo's 0.33 mi ~7 min
2731 Castro Valley Boulevard
Restaurant Tacos El Compa 0.33 mi ~7 min
2788 Castro Valley Boulevard
Restaurant Burger King 0.34 mi ~7 min
2757 Castro Valley Boulevard, Castro Valley 94546-5411
06:00-22:00
Parking 3Crosses Church 0.43 mi ~9 min
N Side Of Foothill Blvd @ John Dr (Near I-580), Castro Valley 94546
Coffee Cafe 4 0.45 mi ~10 min
Hotel Holiday Inn Express 0.46 mi ~10 min
2419;2421 Castro Valley Boulevard
Parking John Drive Park and Ride 0.48 mi ~10 min
N. side of Foothill Blvd. at John Dr. (near I-580), CASTRO VALLEY 94546
Distances are straight‑line estimates — walking routes may be longer. Hours and phone numbers can change; call ahead to confirm.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 1118626 | CA | Internal Medicine Physician |
| 56261 | TN | Internal Medicine Physician |
| A152926 | CA | Hospitalist Physician primary |
Licences are recorded in 2 states: CA, TN. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Internal Medicine
- PAC ID
- 5799045316
Enrolled in Medicare 3 times, across 3 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Tennessee | I20180130002168 | Practitioner - Internal Medicine |
| California | I20190808001082 | Practitioner - Internal Medicine |
| Texas | I20211222000859 | Practitioner - Internal Medicine |
Medicare enrolment is recorded as approved under the provider type Practitioner - Internal Medicine. There are 3 separate enrolment records across 3 states (TN, CA, TX). 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.
Licensed in 2 states
This provider holds licences in 2 states: California and Tennessee. The practice address on file is in Castro Valley, 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
- 1118626
- Specialty
- Internal Medicine 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 Hospitalist covers
Hospitalists are physicians whose primary professional focus is the general medical care of hospitalized patients. Their activities include patient care, teaching, research, and leadership related to Hospital Medicine. The term 'hospitalist' refers to physicians whose practice emphasizes providing care for hospitalized patients. NUCC Health Care Provider Taxonomy, code 208M00000X
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 | 1118626 | CA | |
| 207R00000X | Internal Medicine Physician | 56261 | TN | |
| 208M00000X | Hospitalist Physician | A152926 | CA | 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 | 1003235243 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 15, 2014 |
| Last updated | Mar 7, 2023 |
| Status | Active |
| Sole proprietor | No |
| Gender | Male |
| Credential | M.D. |
| Practice address |
20103 LAKE CHABOT RD Castro Valley, CA 94546 (510) 727-3256 Fax (510) 727-3107 |
| Mailing address |
400 CHANEY RD APT 307 Smyrna, TN 37167 |
| Other identifiers |
1118626
· Other (CA) A152926 · Other (CA) |
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 | 0 | 0 | 3 | 2 | 3 | 5 | 2 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 4 | 3 | 1 | 2 | 8 |
Sum = 47 · next multiple of 10 = 50 · check digit = 3 · actual last digit = 3
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.