National Provider Identifier (NPI)

The NPI is the one identifier every payer reads the same way. CMS defines it as a 10-position, intelligence-free numeric identifier: the digits say nothing about the provider’s state or specialty. Covered providers, health plans and clearinghouses must use it on HIPAA transactions, and providers have to share it with anyone who needs it for billing. Numbers are issued through the National Plan and Provider Enumeration System (NPPES), which is also the first step in Medicare enrollment.

Billing uses two kinds. A Type 1 NPI belongs to an individual, such as a physician, therapist or nurse practitioner. A Type 2 NPI belongs to an organization: a group practice, an agency, a transportation company or a clinic. On an 837P or a CMS-1500 the billing provider is usually the Type 2 number and the rendering provider is the Type 1 number, and both have to match what the payer holds in its enrollment file.

The usual mistake is a mismatch. A new clinician’s visits go out under the group’s Type 2 number before the payer has linked her Type 1 number to it, or a solo provider keeps billing under the Type 1 number after incorporating. Both patterns produce identifier denials with remark codes that point at the rendering or billing field. Check the NPI pairing against each payer’s enrollment record before the first claim goes out.