DENNISON WILLIAMS
NPI 1487232757
Specialist/Technologist in San Francisco, CA

NPI Status: Active since March 30, 2021

Contact Information

730 POLK ST FL 4
SAN FRANCISCO, CA
ZIP 94109
Phone: (415) 554-8494
Fax: (415) 554-8444

NPI Profile Information
Primary Taxonomy
NPI Validation
Other Providers Same Location
Frequently Asked Questions

Individual
Male
Specialist/Technologist

About DENNISON WILLIAMS

This page provides the complete NPI Profile along with additional information for Dennison Williams, a provider established in San Francisco, California with a medical specialization in Specialist/technologist. The healthcare provider is registered in the NPI registry with number 1487232757 assigned on March 2021. The practitioner's primary taxonomy code is 225500000X. The provider is registered as an individual and his NPI record was last updated 5 years ago.

NPI: 1487232757
Provider Name: DENNISON WILLIAMS
Gender: Male
Entity Type: Individual
Location Address: 730 POLK ST FL 4 SAN FRANCISCO, CA 94109
Location Phone: (415) 554-8494
Location Fax: (415) 554-8444
Mailing Address: PO BOX 422908 SAN FRANCISCO, CA 94142
Mailing Phone: (503) 481-7640
Is Sole Proprietor?: No
Enumeration Date: 03-30-2021
Last Update Date: 03-30-2021
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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: Specialist/Technologist
Taxonomy Code: 225500000X
Type: Respiratory, Developmental, Rehabilitative and Restorative Service Providers
Taxonomy Description: General classification identifying respiratory, developmental, rehabilitative or restorative services individuals who are trained on a specific piece of equipment or technical procedure.

NPI 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 1487232757, we treat the final digit (7) 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 63. The final step is to find the difference between that total and the next multiple of ten (70 - 63 = 7).

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

Doubled → 2

Pos 2

Unchanged

Pos 3

Doubled → 16 → 1 + 6

Pos 4

Unchanged

Pos 5

Doubled → 4

Pos 6

Unchanged

Pos 7

Doubled → 4

Pos 8

Unchanged

Pos 9

Doubled → 10 → 1 + 0

Check

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 8 → 16 → 7 2 → 4 2 → 4 5 → 10 → 1

Step 2: Add all digits plus the NPI constant

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

2 + 4 + 1 + 6 + 7 + 4 + 3 + 4 + 7 + 1 + 0 + 24 = 63

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

The next multiple of ten after 63 is 70. The difference is the calculated check digit.

70 - 63 = 7

This NPI is valid

The calculated check digit is 7, which matches the last digit of 1487232757.