HIPAA National Identifiers Explained: What NPI, HPID, and Employer EINs Mean for Compliance

Overview of National Provider Identifier

What the NPI is

The National Provider Identifier (NPI) is a 10‑digit, intelligence‑free number that uniquely identifies health care providers in HIPAA transactions. It replaced a patchwork of Legacy Provider Identifiers such as UPINs and payer‑assigned numbers under HIPAA’s Administrative Simplification provisions.

Who needs an NPI

Covered health care providers—individual practitioners (Type 1) and organizations (Type 2)—must obtain an NPI. Organizational providers may assign NPIs to eligible subparts (for example, a hospital’s outpatient pharmacy) when separate identification is needed for Electronic Data Interchange and billing.

Using the NPI in practice

You use the NPI on standard EDI transactions, including eligibility (270/271), claims (837), remittance advice (835), claim status (276/277), prior authorization (278), and others. The NPI identifies who rendered, ordered, referred, billed, or received payment, while taxonomy and other data convey specialty and role.

Maintaining your NPI

Keep your NPI record accurate by updating addresses, endpoints, and taxonomy promptly when business details change. Accurate NPI data helps plans, clearinghouses, and other HIPAA-covered entities route transactions correctly and reduce avoidable rejections.

Role of Employer Identification Number

What the EIN identifies

The IRS Employer Identification Number (EIN) is a 9‑digit taxpayer identifier for businesses, including provider organizations and plan sponsors. It identifies the legal entity responsible for tax reporting, payroll, and premium contributions.

How the EIN appears in HIPAA EDI

In HIPAA transactions, the EIN commonly identifies an employer or plan sponsor in enrollment and premium payment files (for example, the 834 and 820). Payers also use a provider’s EIN/Tax ID alongside the NPI for payment, 1099 reporting, and reconciliation processes.

EIN versus NPI

The NPI identifies the health care provider for Regulatory Compliance with Administrative Simplification; the EIN identifies the legal business for tax and financial purposes. Many transactions carry both values so systems can match the clinical provider (NPI) to the payee entity (EIN) without ambiguity.

Handling and safeguards

While an EIN is not PHI, treat it as sensitive business information. Ensure it is accurate in enrollment, contracting, and banking records to prevent payment delays and downstream EDI mismatches.

History and Status of Health Plan Identifier

Why HPID was proposed

The Health Plan Identifier (HPID) was envisioned as a Unique Health Plan Identifier to standardize how plans are identified in EDI and reduce routing complexity. Earlier rules set issuance timelines, and some entities obtained HPIDs in anticipation of use.

Rescission and current status

Following industry feedback that HPID would not meaningfully improve routing and might conflict with existing payer identifiers, HHS rescinded the HPID requirement in 2019. As of November 7, 2025, HPID remains rescinded and is not used in HIPAA transactions.

What to use instead

Continue to use established payer identifiers and trading partner IDs required by your health plans and clearinghouses. Maintain your NPI for provider identification and your IRS Employer Identification Number for financial and employer‑related functions.

Compliance Requirements for HIPAA-Covered Entities

Who is covered

HIPAA-covered entities include health plans, health care clearinghouses, and health care providers who transmit standard transactions electronically. Business associates supporting these functions must also align with identifier usage in applicable workflows.

Required actions

• Obtain and use NPIs on all standard EDI transactions; accept NPIs from trading partners and avoid using Legacy Provider Identifiers.
• Use your IRS Employer Identification Number where required for tax, payment, and employer/plan sponsor identification.
• Do not use or request HPIDs; they are not part of current Administrative Simplification standards.
• Keep NPI records current in a timely manner and ensure internal systems store NPIs as the authoritative provider identifier.
• Document identifier policies, data governance, and trading partner agreements for audit readiness and Regulatory Compliance.

Common pitfalls to avoid

• Submitting claims with legacy IDs or mismatched NPIs and EINs, leading to denials or misapplied payments.
• Failing to enumerate organizational subparts when operationally necessary, which can hinder routing and contract mapping.
• Relying on payer‑specific IDs in place of the NPI on standard transactions.

Governance and controls

Assign ownership for provider data, validate NPIs and EINs during onboarding, and monitor EDI acknowledgments for identifier errors. Regular internal audits help confirm consistent use of NPIs and EINs across claims, enrollment, and payment processes.

Impact of Identifiers on Electronic Transactions

How identifiers improve EDI

Standard identifiers reduce manual crosswalks, accelerate payment cycles, and improve first‑pass rates. Clean NPIs enable accurate provider matching, while EINs support reconciliation between remittances, deposits, and tax documents across systems.

Where identifiers appear

• Eligibility (270/271): NPI identifies the requesting and servicing provider; payer ID routes the transaction.
• Claims (837): Rendering, billing, and pay‑to providers are identified with NPIs; EIN supports the billing entity for payment and reporting.
• Remittance (835): NPIs tie payments to providers; EIN validates the payee entity for accounting and 1099 purposes.
• Claim Status (276/277) and Prior Authorization (278): NPIs identify involved providers for status inquiries and authorizations.
• Enrollment (834) and Premium Payment (820): EIN identifies employers/plan sponsors; payer identifiers route files to the correct health plan.

Key takeaways

Use the NPI as the universal provider identifier, the EIN for the legal business and employer functions, and established payer IDs for routing. With HPID rescinded, focusing on accurate NPIs and EINs delivers the intended Administrative Simplification benefits of Electronic Data Interchange.

FAQs

What is the purpose of the National Provider Identifier?

The NPI provides a single, standardized identifier for health care providers across all HIPAA transactions. It replaces Legacy Provider Identifiers and enables consistent provider matching, cleaner routing, and fewer claim and payment errors.

How is the Employer Identification Number used in HIPAA transactions?

The EIN identifies the legal business or employer entity in transactions that involve payment and sponsorship. You’ll see it in enrollment (834), premium payment (820), remittance reconciliation (835), and tax reporting, often alongside the NPI for the provider role.

Why was the Health Plan Identifier rescinded?

Industry analysis showed that a Unique Health Plan Identifier would not improve routing and could disrupt existing payer identifier frameworks. HHS rescinded HPID in 2019, and it is not required or used in transactions as of November 7, 2025.

What are the current compliance requirements for HIPAA identifiers?

Obtain and use NPIs in standard transactions, keep NPI data current, use your IRS Employer Identification Number where required for financial and employer functions, and do not use HPIDs. Ensure trading partner agreements and internal controls reflect these practices for ongoing compliance.