Healthcare Provider NPI Lookup • 10-Digit
Free National Provider Identifier (NPI) lookup, Luhn check-digit validator, Type 1 vs Type 2 provider directory, and healthcare taxonomy code reference.
🔎 10-Digit NPI Checksum Calculator & Validator
Enter a 10-digit NPI to verify its mathematical validity under the CMS standard, or enter 9 digits to compute the required 10th check digit.
Valid 10-Digit NPI Number
Mathematical Luhn check passed with prefix constant '80840'.
How does the NPI Luhn Algorithm work?
CMS defines standard NPIs according to ISO 80840 (the international identifier prefix code for United States health care providers):
- Prepend the 5-digit US prefix 80840 to the first 9 digits of the provider identifier (creating a 14-digit sequence).
- Double the value of alternate digits starting from the rightmost position (the 9th NPI digit) working leftward.
- Sum the individual digits of the doubled numbers and intact digits.
- Subtract the sum's ones-digit from 10 (if the remainder is 10, the check digit is 0). The result is the final 10th digit.
🏥 Curated Provider & Organization Directory
Explore prominent medical institutions, health systems, and individual practitioners with official NPI data.
Dr. Sarah Jenkins, MD
Mayo Clinic Hospital - Rochester
The Johns Hopkins Hospital
Cleveland Clinic Foundation
Massachusetts General Hospital
Dr. David Chen, MD
Stanford Health Care
Dr. Elena Rostova, DO
NewYork-Presbyterian Hospital
Dr. Marcus Aurelius Miller, DDS
Cedars-Sinai Medical Center
Dr. Rachel Thorne, PharmD
St. Jude Children's Research Hospital
Dr. Anthony Vance, MD
Northwestern Memorial Hospital
📚 Healthcare Provider Taxonomy Code Reference
Healthcare Provider Taxonomy Codes are 10-character alphanumeric codes maintained by NUCC to categorize provider type, classification, and specialization.
| Taxonomy Code | Classification & Specialty | Provider Grouping |
|---|---|---|
207Q00000X |
Family Medicine | Allopathic & Osteopathic Physicians |
207R00000X |
Internal Medicine | Allopathic & Osteopathic Physicians |
207RC0000X |
Cardiovascular Disease | Allopathic & Osteopathic Physicians |
208000000X |
Pediatrics | Allopathic & Osteopathic Physicians |
2084N0400X |
Neurology | Allopathic & Osteopathic Physicians |
207X00000X |
Orthopaedic Surgery | Allopathic & Osteopathic Physicians |
2085R0202X |
Diagnostic Radiology | Allopathic & Osteopathic Physicians |
1223G0001X |
General Practice Dentistry | Dental Providers |
163W00000X |
Registered Nurse | Nursing Providers |
363A00000X |
Physician Assistant | Physician Assistants & APRNs |
363L00000X |
Nurse Practitioner | Physician Assistants & APRNs |
183500000X |
Pharmacist | Pharmacy Service Providers |
101Y00000X |
Counselor | Behavioral Health & Social Services |
103T00000X |
Psychologist | Behavioral Health & Social Services |
282N00000X |
General Acute Care Hospital | Hospitals & Facilities |
282NC0060X |
Children's Hospital | Hospitals & Facilities |
332B00000X |
Durable Medical Equipment & Supplies | Suppliers |
About this tool
How to use it
- Enter any 10-digit National Provider Identifier (NPI) in the Luhn Validator to inspect its mathematical validity against the official CMS Luhn formula.
- Alternatively, enter a 9-digit base NPI to calculate the required 10th check digit.
- Switch to the Provider Directory tab to search and filter healthcare organizations and practitioners by name, NPI, state, or entity type.
- Browse the Taxonomy Codes tab to look up 10-digit classification codes across medical specialties, hospitals, nursing, and dental providers.
Why it matters
The National Provider Identifier (NPI) is a mandatory 10-digit standard identifier required by HIPAA for all covered healthcare providers, health plans, and healthcare clearinghouses. Validating NPI format and check digits prevents billing rejections, credentialing errors, and electronic claims processing failures.
When to use it
Use this tool when onboarding medical providers, validating provider registries, verifying insurance claim billing details, or checking taxonomy code classifications.
Common questions
What is the difference between an NPI Type 1 and Type 2?
Type 1 NPIs are assigned to individual healthcare practitioners such as physicians, dentists, nurses, and psychologists. Type 2 NPIs are assigned to organizational providers such as hospitals, group practices, home health agencies, and pharmacies.
How is the 10th check digit of an NPI calculated?
The NPI check digit uses the Luhn formula with an initial 80840 prefix (representing United States healthcare providers under ISO 80840). Alternate digits of the 14-digit sequence are doubled, summed, and subtracted from the next multiple of 10.
Does a valid check digit guarantee the NPI is currently active?
No. The Luhn algorithm verifies mathematical validity and syntax. To verify active legal enumeration, disciplinary status, or DEA licensure, cross-reference the official CMS NPPES registry.
What is a Healthcare Provider Taxonomy Code?
A taxonomy code is a 10-character alphanumeric code established by the National Uniform Claim Committee (NUCC) that classifies a provider's primary healthcare specialization, medical grouping, and service scope.