IAN MENDENHALL
NPI 1659176089
Counselor in Longview, WA

NPI Status: Active since February 18, 2025

Contact Information

720 14TH AVE
LONGVIEW, WA
ZIP 98632
Phone: (360) 423-0203
Fax: (360) 423-5086

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

Individual
Male
Counselor

About IAN MENDENHALL

This page provides the complete NPI Profile along with additional information for Ian Mendenhall, a provider established in Longview, Washington with a medical specialization in Counselor. The healthcare provider is registered in the NPI registry with number 1659176089 assigned on February 2025. The practitioner's primary taxonomy code is 101Y00000X with license number CG61657470 (WA). The provider is registered as an individual and his NPI record was last updated one year ago.

NPI: 1659176089
Provider Name: IAN MENDENHALL
Gender: Male
Entity Type: Individual
Location Address: 720 14TH AVE LONGVIEW, WA 98632
Location Phone: (360) 423-0203
Location Fax: (360) 423-5086
Mailing Address: PO BOX 1847 LONGVIEW, WA 98632
Mailing Phone: (360) 423-0203
Mailing Fax: (360) 423-5086
Is Sole Proprietor?: No
Enumeration Date: 02-18-2025
Last Update Date: 02-18-2025
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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: Counselor
Taxonomy Code: 101Y00000X
Type: Behavioral Health & Social Service Providers
License No.: CG61657470
License State: WA
Taxonomy Description: A provider who is trained and educated in the performance of behavior health services through interpersonal communications and analysis. Training and education at the specialty level usually requires a master's degree and clinical experience and supervision for licensure or certification.

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 1659176089, we treat the final digit (9) 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 61. The final step is to find the difference between that total and the next multiple of ten (70 - 61 = 9).

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 → 10 → 1 + 0

Pos 4

Unchanged

Pos 5

Doubled → 2

Pos 6

Unchanged

Pos 7

Doubled → 12 → 1 + 2

Pos 8

Unchanged

Pos 9

Doubled → 16 → 1 + 6

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 5 → 10 → 1 1 → 2 6 → 12 → 3 8 → 16 → 7

Step 2: Add all digits plus the NPI constant

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

2 + 6 + 1 + 0 + 9 + 2 + 7 + 1 + 2 + 0 + 1 + 6 + 24 = 61

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

The next multiple of ten after 61 is 70. The difference is the calculated check digit.

70 - 61 = 9

This NPI is valid

The calculated check digit is 9, which matches the last digit of 1659176089.