Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 30 days.

DR. WILLIAM JOSEPH LEONARD DDS
NPI 1710948310
Dentist - General Practice in Bethesda, MD

Active since March 31, 2006
8901 WISCONSIN AVENUE, BETHESDA, MD 20889(301) 319-4794 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: July 19, 2026.

  • Individual
  • Male
  • Dentist
  • General Practice

About WILLIAM LEONARD

This page provides the complete NPI Profile along with additional information for William Leonard, a provider established in Bethesda, Maryland with a medical specialization in Dentist, focusing in general practice . The healthcare provider is registered in the NPI registry with number 1710948310 assigned on March 2006. The practitioner's primary taxonomy code is 1223G0001X with license number 12588 (TX). The provider is registered as an individual and his NPI record was last updated July 2026.

NPI
1710948310
Provider Name
DR. WILLIAM JOSEPH LEONARD DDS
Gender
Male
Entity Type
Individual
Location Address
8901 WISCONSIN AVENUE BETHESDA, MD 20889
Location Phone
(301) 319-4794
Mailing Address
22 HAYEK ST BEAUFORT, SC 29907
Mailing Phone
(843) 525-6358
Is Sole Proprietor?
No
Enumeration Date
03-31-2006
Last Update Date
07-13-2026
Code Navigator

A dentist like William Leonard is a skilled in and licensed provider that diagnoses and treats problems with patients teeth, gums, and related parts of the mouth. Dentists educate patients on how to take care of the teeth and gums and provide information on diet choices that affect oral health. Dentists must be licensed in the state in which they work.

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

Dentist General Practice

Taxonomy Code
1223G0001X
Type
Dental Providers
License No.
12588
License State
TX
Taxonomy Description
A general dentist is the primary dental care provider for patients of all ages. The general dentist is responsible for the diagnosis, treatment, management and overall coordination of services related to patients' oral health 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 1710948310, we treat the final digit (0) 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 60. The final step is to find the difference between that total and the next multiple of ten (60 - 60 = 0).

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.

Pos 1
1
Doubled → 2
Pos 2
7
Unchanged
Pos 3
1
Doubled → 2
Pos 4
0
Unchanged
Pos 5
9
Doubled → 18 → 1 + 8
Pos 6
4
Unchanged
Pos 7
8
Doubled → 16 → 1 + 6
Pos 8
3
Unchanged
Pos 9
1
Doubled → 2
Check
0
Target digit
Regular digit Doubled digit Check digit

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.

1 → 2 1 → 2 9 → 18 → 9 8 → 16 → 7 1 → 2

Step 2: Add all digits plus the NPI constant

Add the transformed values, the unchanged digits, and the constant 24.

2 + 7 + 2 + 0 + 1 + 8 + 4 + 1 + 6 + 3 + 2 + 24 = 60

Step 3: Find the amount needed to reach the next multiple of 10

The next multiple of ten after 60 is 60. The difference is the calculated check digit.

60 - 60 = 0
This NPI is valid
The calculated check digit is 0, which matches the last digit of 1710948310.

Other Providers at the Same Location


The following 20 providers are registered at the same or a nearby location.

Ophthalmology
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Ophthalmology
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Family Medicine
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Dentist (General Practice)
8901 WISCONSIN AVENUE, NATIONAL NAVAL MEDICAL CENTER
BETHESDA, MD 20889
Emergency Medicine
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Internal Medicine (Pulmonary Disease)
8901 WISCONSIN AVENUE, NATIONAL NAVAL MEDICAL CENTER
BETHESDA, MD 20889
Physical Therapist
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Internal Medicine (Pulmonary Disease)
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Allergy & Immunology
8901 WISCONSIN AVENUE, NNMC, BUILDING 9, ALLERGY/IMM. CLINIC
BETHESDA, MD 20889
Social Worker (Clinical)
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Orthopaedic Surgery
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Nurse Practitioner (Adult Health)
8901 WISCONSIN AVENUE, WALTER REED NATIONAL MILITARY MEDICAL CENTER
BETHESDA, MD 20889
Psychiatry & Neurology (Neurology)
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Student in an Organized Health Care Education/Training Program
8901 WISCONSIN AVENUE, WALTER REED NATIONAL MILITARY MEDICAL CENTER
BETHESDA, MD 20889
Dentist (General Practice)
8901 WISCONSIN AVENUE, BUILDING 9, 2ND FLOOR
BETHESDA, MD 20889
Internal Medicine
8901 WISCONSIN AVENUE, DEPT OF INTERNAL MEDICINE - NNMC
BETHESDA, MD 20889
Internal Medicine (Interventional Cardiology)
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Internal Medicine
8901 WISCONSIN AVENUE
BETHESDA, MD 20889
Internal Medicine
8901 WISCONSIN AVENUE, NATIONAL NAVAL MEDICAL CENTER
BETHESDA, MD 20889
Physician Assistant (Medical)
8901 WISCONSIN AVENUE, DEPARTMENT OF CARDIOLOGY
BETHESDA, MD 20889

Frequently Asked Questions

The NPI number assigned to this healthcare provider is 1710948310, enumerated as an "individual" on March 31, 2006.

The provider is located at 8901 WISCONSIN AVENUE BETHESDA, MD 20889 and the phone number is (301) 319-4794.

Dentist with taxonomy code 1223G0001X and a focus in General Practice.