Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 30 days.

DR. LES PERKOWSKI D.O.
NPI 1710955604
Psychiatry & Neurology - Psychiatry in Dixon, IL

Active since March 08, 2006
403 E 1ST ST, DIXON, IL 61021(815) 285-5635(815) 285-5851 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: July 19, 2026.

  • Individual
  • Male
  • Psychiatry & Neurology
  • Psychiatry

About LES PERKOWSKI

This page provides the complete NPI Profile along with additional information for Les Perkowski, a provider established in Dixon, Illinois with a medical specialization in Psychiatry & Neurology, focusing in psychiatry . The healthcare provider is registered in the NPI registry with number 1710955604 assigned on March 2006. The practitioner's primary taxonomy code is 2084P0800X. The provider is registered as an individual and his NPI record was last updated July 2026.

NPI
1710955604
Provider Name
DR. LES PERKOWSKI D.O.
Gender
Male
Entity Type
Individual
Location Address
403 E 1ST ST DIXON, IL 61021
Location Phone
(815) 285-5635
Location Fax
(815) 285-5851
Mailing Address
403 E 1ST ST DIXON, IL 61021
Mailing Phone
(815) 285-5635
Mailing Fax
(815) 285-5851
Is Sole Proprietor?
No
Enumeration Date
03-08-2006
Last Update Date
07-13-2026
Code Navigator

A psychiatrist like Les Perkowski are primary mental health physicians diagnose and treat mental illnesses through psychotherapy, psychoanalysis, hospitalization and medication. Psychiatrist help patients find solutions through changes in their behavioral patterns, explorations of experiences, group and family therapy.

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

Psychiatry & Neurology Psychiatry

Taxonomy Code
2084P0800X
Type
Allopathic & Osteopathic Physicians
License State
IL
Taxonomy Description
A Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual and gender identity disorders and adjustment disorders. Biologic, psychological, and social components of illnesses are explored and understood in treatment of the whole person. Tools used may include diagnostic laboratory tests, prescribed medications, evaluation and treatment of psychological and interpersonal problems with individuals and families, and intervention for coping with stress, crises, and other problems.

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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 1710955604, 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
1
Doubled → 2
Pos 2
7
Unchanged
Pos 3
1
Doubled → 2
Pos 4
0
Unchanged
Pos 5
9
Doubled → 18 → 1 + 8
Pos 6
5
Unchanged
Pos 7
5
Doubled → 10 → 1 + 0
Pos 8
6
Unchanged
Pos 9
0
Doubled → 0
Check
4
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 1 → 2 9 → 18 → 9 5 → 10 → 1 0 → 0

Step 2: Add all digits plus the NPI constant

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

2 + 7 + 2 + 0 + 1 + 8 + 5 + 1 + 0 + 6 + 0 + 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 1710955604.

Other Providers at the Same Location


The following 20 providers are registered at the same or a nearby location.

Anesthesiology
403 E 1ST ST
DIXON, IL 61021
Physical Therapist
403 E 1ST ST
DIXON, IL 61021
Physical Therapy Assistant
403 E 1ST ST
DIXON, IL 61021
Physical Therapist
403 E 1ST ST
DIXON, IL 61021
Occupational Therapist
403 E 1ST ST, KSB HOSPITAL
DIXON, IL 61021
Physical Therapist
403 E 1ST ST
DIXON, IL 61021
Physical Therapist
403 E 1ST ST
DIXON, IL 61021
Speech-Language Pathologist
403 E 1ST ST
DIXON, IL 61021
Emergency Medicine
403 E 1ST ST
DIXON, IL 61021
Anesthesiology
403 E 1ST ST
DIXON, IL 61021
Pharmacy (Community/Retail Pharmacy)
403 E 1ST ST
DIXON, IL 61021
Medicare Defined Swing Bed Unit
403 E 1ST ST
DIXON, IL 61021
Family Medicine
403 E 1ST ST
DIXON, IL 61021
Emergency Medicine
403 E 1ST ST
DIXON, IL 61021
Pathology (Anatomic Pathology & Clinical Pathology)
403 E 1ST ST
DIXON, IL 61021
Surgery
403 E 1ST ST
DIXON, IL 61021
Social Worker (Clinical)
403 E 1ST ST
DIXON, IL 61021
Social Worker (Clinical)
403 E 1ST ST
DIXON, IL 61021
Nurse Practitioner (Family)
403 E 1ST ST
DIXON, IL 61021
Nurse Practitioner (Family)
403 E 1ST ST
DIXON, IL 61021

Frequently Asked Questions

The NPI number assigned to this healthcare provider is 1710955604, enumerated as an "individual" on March 08, 2006.

The provider is located at 403 E 1ST ST DIXON, IL 61021 and the phone number is (815) 285-5635.

Psychiatry & Neurology with taxonomy code 2084P0800X and a focus in Psychiatry.