ALEXANDER JOSEPH WHALEN PMHNP-BC
NPI 1265309777
Nurse Practitioner - Psychiatric/Mental Health in Oak Brook, IL

NPI Status: Active since October 20, 2025

Contact Information

1200 HARGER RD STE 200
OAK BROOK, IL
ZIP 60523
Phone: (630) 556-8914

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

Individual
Male
Nurse Practitioner
Psychiatric/Mental Health

About ALEXANDER WHALEN

This page provides the complete NPI Profile along with additional information for Alexander Whalen, a provider established in Oak Brook, Illinois with a medical specialization in Nurse Practitioner, focusing in psychiatric/mental health . The healthcare provider is registered in the NPI registry with number 1265309777 assigned on October 2025. The practitioner's primary taxonomy code is 363LP0808X with license number 209.033464 (IL). The provider is registered as an individual and his NPI record was last updated one year ago.

NPI: 1265309777
Provider Name: ALEXANDER JOSEPH WHALEN PMHNP-BC
Gender: Male
Entity Type: Individual
Location Address: 1200 HARGER RD STE 200 OAK BROOK, IL 60523
Location Phone: (630) 556-8914
Mailing Address: 1756 W ORCHARD RD UNIT 211 NORTH AURORA, IL 60542
Is Sole Proprietor?: Yes
Enumeration Date: 10-20-2025
Last Update Date: 10-20-2025
Code Navigator

A nurse practitioner (NP) like Alexander Whalen is an experienced registered nurse with a master’s or doctoral degree and advanced clinical training. Nurse practitioners can work in many different specialties including primary care, pediatrics, cardiology, emergency, women’s health, oncology or geriatrics. Nurse practitioners provide services like physical exams, order laboratory tests, manage diseases, write prescriptions, etc.

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: Nurse Practitioner Psychiatric/Mental Health
Taxonomy Code: 363LP0808X
Type: Physician Assistants & Advanced Practice Nursing Providers
License No.: 209.033464
License State: IL

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 1265309777, 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 → 12 → 1 + 2

Pos 4

Unchanged

Pos 5

Doubled → 6

Pos 6

Unchanged

Pos 7

Doubled → 18 → 1 + 8

Pos 8

Unchanged

Pos 9

Doubled → 14 → 1 + 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 6 → 12 → 3 3 → 6 9 → 18 → 9 7 → 14 → 5

Step 2: Add all digits plus the NPI constant

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

2 + 2 + 1 + 2 + 5 + 6 + 0 + 1 + 8 + 7 + 1 + 4 + 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 1265309777.