DENNIS NATHAN CONTRERAS
NPI 1881587657
Nurse Practitioner - Family in Wellsville, NY

NPI Status: Active since May 31, 2025

Contact Information

191 N MAIN ST
WELLSVILLE, NY
ZIP 14895
Phone: (585) 991-8841

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

Individual
Male
Nurse Practitioner
Family

About DENNIS CONTRERAS

This page provides the complete NPI Profile along with additional information for Dennis Contreras, a provider established in Wellsville, New York with a medical specialization in Nurse Practitioner, focusing in family . The healthcare provider is registered in the NPI registry with number 1881587657 assigned on May 2025. The practitioner's primary taxonomy code is 363LF0000X with license number 357108 (NY). The provider is registered as an individual and his NPI record was last updated February 2026.

NPI: 1881587657
Provider Name: DENNIS NATHAN CONTRERAS
Gender: Male
Entity Type: Individual
Location Address: 191 N MAIN ST WELLSVILLE, NY 14895
Location Phone: (585) 991-8841
Mailing Address: 10267 STATE ROUTE 36 DANSVILLE, NY 14437
Mailing Phone: (585) 991-8841
Is Sole Proprietor?: Yes
Enumeration Date: 05-31-2025
Last Update Date: 02-20-2026
Code Navigator

A nurse practitioner (NP) like Dennis Contreras 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 Family
Taxonomy Code: 363LF0000X
Type: Physician Assistants & Advanced Practice Nursing Providers
License No.: 357108
License State: NY

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 1881587657, 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 → 16 → 1 + 6

Pos 4

Unchanged

Pos 5

Doubled → 10 → 1 + 0

Pos 6

Unchanged

Pos 7

Doubled → 14 → 1 + 4

Pos 8

Unchanged

Pos 9

Doubled → 10 → 1 + 0

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 8 → 16 → 7 5 → 10 → 1 7 → 14 → 5 5 → 10 → 1

Step 2: Add all digits plus the NPI constant

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

2 + 8 + 1 + 6 + 1 + 1 + 0 + 8 + 1 + 4 + 6 + 1 + 0 + 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 1881587657.