Novice Know How: What is the Difference Between a Medicare Provider Identification Number (PIN) and the Unique Provider Identification Number (UPIN)?
The Medicare Carrier's Provider Enrollment department issues Medicare Providers a Medicare Billing Number called the Provider Identification Number (PIN). Once the Carrier has issued the PIN, a Unique Provider Identification Number (UPIN) is issued to the provider through the UPIN Registry. The PIN is used for billing purposes and the UPIN is used for ordering and referring purposes. A 'Referring Provider' sends (refers) a patient to another provider for services. An 'Ordering Provider' orders services or tests for a patient.
PIN
A Medicare Provider must have a PIN for each entity they work for. The PIN identifies who rendered services to a Medicare Beneficiary on the CMS-1500 Claim Form or on an electronically submitted claim. A group claim will include both the Group PIN and the Member PIN (who rendered the service). An individual or solo provider's claim will only need the individual's PIN. See 'How to complete the CMS-1500 Claim Form' at the following Website:
http://www.cms.hhs.gov/manuals/
downloads/clm104c26.pdf 
For providers that submit electronic claims, a cross reference guide appears on pages 88 - 96 of the General Medicare guidebook. It's available on the WPS Medicare Website.
Claims without a PIN will be returned as unprocessable. There are no appeal rights for claims deemed unprocessable; you must correct the claim and resubmit it.
UPIN
The National UPIN Registry, located in California, issues a unique UPIN to each individual provider/supplier. This UPIN is used on claims to identify any referring or ordering services. A provider may have several PINs, but a provider will only have one (1) UPIN. To check on a provider's UPIN you may go to: http://www.upinregistry.com/ 
Only Provider/Suppliers reimbursed from the Physicians Fee Schedule will receive a notice regarding their UPIN.
Certain services require that the provider's UPIN appear on the CMS-1500 Claim Form. Claims will be returned as unprocessable if the UPIN, along with the referring/ordering provider's name, is not present.
With the implementation of the National Provider Identifier (NPI), the PIN and UPIN will be slowly replaced. The PIN will become known as the 'Legacy' number. Claims will be 'crosswalked' from the NPI to the PIN for payment purposes.
A helpful CMS Website for NPI information is:
http://www.cms.hhs.gov/National
ProvIdentStand/04_education.asp#TopOfPage
Page Last Updated: Monday, 09-Jun-2008 15:27:27 CDT
