JOHNNA AGGELIKAS
NPI 1659216828
Counselor - Mental Health in Lexington, MA

NPI Status: Active since April 22, 2026

Contact Information

125 HARTWELL AVE
LEXINGTON, MA
ZIP 02421
Phone: (781) 861-0890

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

Individual
Female
Counselor
Mental Health

About JOHNNA AGGELIKAS

This page provides the complete NPI Profile along with additional information for Johnna Aggelikas, a provider established in Lexington, Massachusetts with a medical specialization in Counselor, focusing in mental health . The healthcare provider is registered in the NPI registry with number 1659216828 assigned on April 2026. The practitioner's primary taxonomy code is 101YM0800X. The provider is registered as an individual and her NPI record was last updated April 2026.

NPI: 1659216828
Provider Name: JOHNNA AGGELIKAS
Gender: Female
Entity Type: Individual
Location Address: 125 HARTWELL AVE LEXINGTON, MA 02421
Location Phone: (781) 861-0890
Mailing Address: 125 HARTWELL AVE LEXINGTON, MA 02421
Is Sole Proprietor?: Yes
Enumeration Date: 04-22-2026
Last Update Date: 04-22-2026
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A mental health counselor like Johnna Aggelikas provides treatment to individuals, families, couples, and groups for mental and emotional health issues and relationship problems. Mental health counselors treat clients with a variety of conditions, including anxiety, depression, grief, low self-esteem, stress, and suicidal impulses.

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 Mental Health
Taxonomy Code: 101YM0800X
Type: Behavioral Health & Social Service Providers
License State: MA

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 1659216828, we treat the final digit (8) 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 62. The final step is to find the difference between that total and the next multiple of ten (70 - 62 = 8).

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 → 4

Pos 6

Unchanged

Pos 7

Doubled → 12 → 1 + 2

Pos 8

Unchanged

Pos 9

Doubled → 4

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 2 → 4 6 → 12 → 3 2 → 4

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 + 4 + 1 + 1 + 2 + 8 + 4 + 24 = 62

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

The next multiple of ten after 62 is 70. The difference is the calculated check digit.

70 - 62 = 8

This NPI is valid

The calculated check digit is 8, which matches the last digit of 1659216828.