JONATHAN RYAN MAH RADT
NPI 1124905484
Counselor - Addiction (Substance Use Disorder) in Grass Valley, CA

NPI Status: Active since August 19, 2025

Contact Information

159 BRENTWOOD DR
GRASS VALLEY, CA
ZIP 95945
Phone: (530) 273-9541

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

Individual
Male
Counselor
Addiction (Substance Use Disorder)

About JONATHAN MAH

This page provides the complete NPI Profile along with additional information for Jonathan Mah, a provider established in Grass Valley, California with a medical specialization in Counselor, focusing in addiction (substance use disorder) . The healthcare provider is registered in the NPI registry with number 1124905484 assigned on August 2025. The practitioner's primary taxonomy code is 101YA0400X with license number R1623720725 (CA). The provider is registered as an individual and his NPI record was last updated one year ago.

NPI: 1124905484
Provider Name: JONATHAN RYAN MAH RADT
Gender: Male
Entity Type: Individual
Location Address: 159 BRENTWOOD DR GRASS VALLEY, CA 95945
Location Phone: (530) 273-9541
Mailing Address: 406 SUNRISE AVE STE 105 ROSEVILLE, CA 95661
Is Sole Proprietor?: Yes
Enumeration Date: 08-19-2025
Last Update Date: 08-19-2025
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A Substance Abuse or Addiction Counselor like Jonathan Mah advices patients who experience alcoholism, drug addiction, eating disorders, mental health issues, or other mental or behavioral problems. Substance Abuse counselors provide treatment and support to help clients recover from addiction or modify problem behaviors. Many counselors incorporate the principles of 12-step programs, such as Alcoholics Anonymous (AA). They educate clients how to cope with stress and life’s issues in ways that help them recover. Counselors also help patients improve their personal relationships and find ways to discuss their addiction or other problems with family and friends.

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: Counselor Addiction (Substance Use Disorder)
Taxonomy Code: 101YA0400X
Type: Behavioral Health & Social Service Providers
License No.: R1623720725
License State: CA

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 1124905484, we treat the final digit (4) 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 56. The final step is to find the difference between that total and the next multiple of ten (60 - 56 = 4).

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 → 4

Pos 4

Unchanged

Pos 5

Doubled → 18 → 1 + 8

Pos 6

Unchanged

Pos 7

Doubled → 10 → 1 + 0

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 2 → 4 9 → 18 → 9 5 → 10 → 1 8 → 16 → 7

Step 2: Add all digits plus the NPI constant

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

2 + 1 + 4 + 4 + 1 + 8 + 0 + 1 + 0 + 4 + 1 + 6 + 24 = 56

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

The next multiple of ten after 56 is 60. The difference is the calculated check digit.

60 - 56 = 4

This NPI is valid

The calculated check digit is 4, which matches the last digit of 1124905484.