DR. JOHN T TSAI M.D.
NPI 1376527366
Pediatrics - Adolescent Medicine in Fairfax, VA
- Individual
- Male
- Pediatrics
- Adolescent Medicine
About JOHN TSAI
This page provides the complete NPI Profile along with additional information for John Tsai, a pediatrician established in Fairfax, Virginia with a medical specialization in Pediatrics, focusing in adolescent medicine . The healthcare provider is registered in the NPI registry with number 1376527366 assigned on December 2005. The practitioner's primary taxonomy code is 2080A0000X with license number 0101238865 (VA). The provider is registered as an individual and his NPI record was last updated July 2026.
- NPI
- 1376527366
- Provider Name
- DR. JOHN T TSAI M.D.
- Gender
- Male
- Entity Type
- Individual
- Location Address
- 3650 JOSEPH SIEWICK DR SUITE 101 FAIRFAX, VA 22033
- Location Phone
- (703) 391-0900
- Location Fax
- (703) 391-2919
- Mailing Address
- 3650 JOSEPH SIEWICK DR SUITE 101 FAIRFAX, VA 22033
- Mailing Phone
- (703) 391-0900
- Mailing Fax
- (703) 391-2919
- Is Sole Proprietor?
- No
- Enumeration Date
- 12-02-2005
- Last Update Date
- 07-13-2026
- Code Navigator
A pediatrician like John Tsai is a physician who has completed a pediatric residency and is board-certified or board-eligible in a pediatric specialty. Pediatric care providers are trained to care for newborns, infants, children and adolescents. A pediatrician could perform physical exams, manage vaccinations, monitor development milestones, diagnose illnesses, infections, injuries or other health problems, etc.
Location Map
Specialty - Primary Taxonomy
The NPI enumerator requires providers to submit at least one taxonomy code. A taxonomy code is a unique 10-character code that describes the healthcare provider type, classification, and the area of specialization. There could be only one primary taxonomy code per NPI record. For individual NPIs the license data is associated to the taxonomy code.
- Classification
Pediatrics Adolescent Medicine
- Taxonomy Code
- 2080A0000X
- Type
- Allopathic & Osteopathic Physicians
- License No.
- 0101238865
- License State
- VA
- Taxonomy Description
- A pediatrician who specializes in adolescent medicine is a multi-disciplinary healthcare specialist trained in the unique physical, psychological and social characteristics of adolescents, their healthcare problems and needs.
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NPI Number Validation
How NPI Validation Works
The NPI validation process uses the ISO-standard Luhn algorithm, a mathematical "handshake", to ensure that a provider's 10-digit ID is authentic and free of common typing errors.
To verify the NPI 1376527366, we treat the final digit (6) as the Check Digit—the target answer we need to reach. The process begins by taking the first nine digits and adding a constant value of 24, which accounts for the "80840" prefix required for all U.S. health identifiers. We then double every other digit starting from the right and sum the individual digits of those results together. For this specific NPI, that total comes to 54. The final step is to find the difference between that total and the next multiple of ten (60 - 54 = 6).
Digit-by-digit view
Use the first nine digits for the calculation. Starting from the right, double every other digit. The last digit is the check digit and is not part of the calculation.
Step 1: Double every other digit from the right
Starting with the rightmost digit of the first nine digits, double every other value. If doubling creates a two-digit number, add those digits together.
Step 2: Add all digits plus the NPI constant
Add the transformed values, the unchanged digits, and the constant 24.
Step 3: Find the amount needed to reach the next multiple of 10
The next multiple of ten after 54 is 60. The difference is the calculated check digit.
Other Providers at the Same Location
The following 20 providers are registered at the same or a nearby location.
FAIRFAX, VA 22033
FAIRFAX, VA 22033
FAIRFAX, VA 22033
FAIRFAX, VA 22033
FAIRFAX, VA 22033
FAIRFAX, VA 22033
FAIRFAX, VA 22033
Frequently Asked Questions
The NPI number assigned to this healthcare provider is 1376527366, enumerated as an "individual" on December 02, 2005.
The provider is located at 3650 JOSEPH SIEWICK DR SUITE 101 FAIRFAX, VA 22033 and the phone number is (703) 391-0900.
Pediatrics with taxonomy code 2080A0000X and a focus in Adolescent Medicine.
