Health care professionals: Using your NPI in HIPAA standard electronic transactions

Federal regulations require you to submit HIPAA standard electronic transactions with only your NPI number. Additional information on this requirement follows.


Which HIPAA standard electronic transactions have to include the NPI?

  • Claim
  • Encounter
  • Eligibility
  • Claim status inquiry
  • Electronic remittance advice (ERA)
  • Precertification add
  • Referral add
  • NCPDP – Pharmacy

How do I use my NPI?
Health care providers must use their NPIs on electronic transactions adopted by the Health Insurance Portability and Accountability Act of 1996 (HIPAA). Additionally, health care providers need an NPI so they can be identified on electronic transactions performed by other entities. For example, pharmacies must use the NPI of the prescribing physician to submit a claim.

Also, health care providers need the NPIs of referring physicians to submit their own claims electronically. And hospitals need the NPIs of admitting and attending physicians to submit electronic claims to a health plan. We strongly urge providers to share their NPIs with these other entities. For additional information, see our guidance on submitting NPIs for organizations in transactions.

If you are not using your NPI in electronic transactions, contact your EDI vendor to find out the steps you need to take to begin including NPIs in your transactions. If you use a Web-based solution, refer to that website for information.

If you submit electronic transactions using computer software, contact your computer system vendor support area for assistance.

Does the NPI replace the tax ID number?

The billing provider's tax ID number and NPI are always required on claims. Any other providers identified on the claim, such as rendering provider or service facility, must be identified with their NPI only. Their tax ID number should not be included.

For eligibility, claim status inquiry, referral and precertification, only the NPI (no tax ID number) is used. However, we must have been informed of the provider's NPI, and it must have been loaded into our provider database.

Is Aetna maintaining old and generating new Aetna provider identification numbers?

We continue to maintain old and generate new Aetna provider ID numbers in our systems since they are needed for other processes not encompassed by the NPI regulation.

Are providers allowed to send other identification numbers, such as PIN, PVN and TIN, in electronic transactions?
To be compliant with the regulations, covered entities must use the NPI of any health care provider (or subpart) that has been assigned an NPI to identify that health care provider in HIPAA standard transactions. The use of other IDs is only permitted to identify:

An entity or individual "as a taxpayer" using the TIN (for example, Social Security number or employer identification number (EIN)). This exception only applies to billing providers in claims and payees in remittance advices. An NPI must also be used to identify covered health care providers "as providers" in these situations.

  • Providers acting in a way that is not considered to be a "provider" role, such as information submitter or receiver or utilization management organization.
  • Non-covered health care providers. For example, a referring provider who does not conduct any electronic transactions is a non-covered provider who may have chosen not to obtain an NPI.
  • Individuals and entities who are not considered health care providers (also known as atypical providers). Atypical providers are persons or groups whose services may be paid for by health benefits plans but who do not directly provide health care. Some common examples include:
    • Personal care workers (for example, aides providing assistance with daily living)
    • Non-medical living arrangements (for example, assisted living, certified family homes, boarding homes, supervised independent living and community residential facilities)
    • Non-emergency transportation providers (for example, taxi services)
  • Entities that administer health benefits but do not directly provide health care, such as:
    • Other health plans
    • Individual practice associations (IPAs)

For more information, see CMS' answer to question ID 5816 at

I submit electronic transactions but am not eligible for an NPI. How do I notify Aetna?
Notify us by using our NPI Exemption Notification Form.

My organization has multiple NPIs. Which should I use in transactions?
View our help document for guidance on submitting transactions with NPIs for organizations.

Claims & encounters

Does the NPI replace the tax ID number on claims?
The billing provider's tax ID number and NPI are always required on claims. Any other providers identified on the claim, such as rendering provider or service facility, must be identified with their NPI only. Their tax ID number should not be included.

Has the NPI changed the way Aetna pays claims and to whom?
No, the NPI did not cause any change to claims adjudication. We use the billing provider tax ID number and provider name and address. The NPI can also be used to identify the appropriate provider.

Does Aetna require the NPI on paper claims?
Regulations only require the use of NPIs on electronic transactions. However, the professional and institutional paper claims forms (CMS [previously HCFA] 1500 version 12/90 and UB-92) were revised to allow NPIs to be included. We recommend you send, but do not require, NPIs on the revised forms (CMS 1500 version 08/2005 and UB-04). Additional information on the new CMS 1500 form is available at Select “1500 Claim Form,” then “1500 Instructions.” You may also subscribe to the UB-04 manual; visit

We also accept, but do not require, the use of legacy ID numbers on paper claims forms. To ensure timely, accurate claims payment, we recommend that paper forms be completed with either the NPI or the legacy ID.

Does Aetna require the referring physician's NPI on claims?
No. While we do not require this information for claims adjudication, it may be necessary for you to send it in order to comply with HIPAA regulations.

How is Aetna processing claims that were previously submitted with Medicare OSCAR numbers?

Note: OSCAR numbers, commonly referred to as UPIN or MPN, are six-digit Medicare provider numbers issued to facilities.

To comply with the regulations, use of a Medicare provider number is not permitted on electronic claims. Because of this, we require an NPI, or an NPI and taxonomy code, on institutional claims where the submission of a Medicare provider number was required by Aetna. Depending on your current setup, you may or may not be required to submit a taxonomy code to Aetna.
Institutional providers that currently bill Medicare for subparts are required to use taxonomy codes on their claims to Aetna. All other providers are encouraged to use taxonomy codes to help ensure accurate identification, but submission of taxonomy codes is not required.

For situations where a provider is unable to send his or her claims electronically, the billing facility taxonomy code should be formatted on the UB-04 paper claim form in field 81cc, preceded with the qualifier B3.

Another payer has notified me that in addition to my NPI, I must submit a different tax ID number on my claims. Should I make the same change in my Aetna claims submissions?
Some providers have multiple tax ID numbers, for example, SSN and EIN or multiple EINs. We are aware that other payers, such as Medicare, have asked some providers to submit claims with a different tax ID number than they used in the past. However, if you make changes to the tax ID number on your Aetna claims, it may affect our ability to process your claims in a timely manner.

If you want to change your tax ID number for Aetna, you can communicate this change as you do any other demographic update by doing one of the following:

  • Contacting our Provider Service Center
  • Contacting your network account manager
  • Utilizing the “Data Maintenance” area of our secure provider website via NaviNet® under the Aetna Plan Central section (for registered users)

My claim was rejected for missing “Billing Provider” NPI. What action do I need to take on these claims to have them processed?
For claims that reject for National Provider Identifier, use the NPI as the primary ID for the Billing Provider and resubmit electronically.

What error codes will I see if my claim submissions reject for no NPI?

Depending on the format of your vendor's claim status report, you may see codes as listed below and/or text similar to that below:

Code Text
A3 -- Acknowledgement/Returned as unprocessable claim. The claim/encounter has been rejected and has not been entered into the adjudication system.
562 -- National Provider Identifier (NPI)
85 --  Billing Provider

Remittance advice

Does Aetna include NPIs on Explanation of Benefits (EOB) formats other than the electronic remittance advice (ERA)?
Only electronic remittance advices include NPIs at this time.

If an electronic remittance advice (ERA) can have a different NPI than submitted on the claim, how can I tell which claim the ERA is responding to?
The submitter's claim number (from CLM01 in an 837 EDI claim) is returned in the CLP01 element in the 835 ERA, and this is not affected by the NPI regulations or related changes. The 835 ERA implementation guide states the following about the CLP01: "This data element is the primary key for posting the remittance information into the provider's database. We also recommend that it be used for that purpose rather than matching by provider IDs."
Matching remittances to claims using the provider ID is normally not necessary.

Is the NPI from the claim included on the payee's electronic remittance advice (ERA), or does Aetna derive the NPI from its internal database?

ERAs include the billing provider's NPI unless you request otherwise. You can request that the payee NPI on the ERA be an NPI you shared with us. For more information, please view the ERA document.

Do new agreements need to be signed for electronic funds transfer (EFT) as a result of the NPI?

No, new agreements do not need to be signed as a result of the NPI. Eligibility, Claim Status Inquiry, Referral, Precertification.

Does the NPI replace the tax ID number on eligibility, claim status inquiry, referral and precertification transactions?

For eligibility, referral and precertification transactions, federal regulations require submission of the provider's NPI number unless the provider is not considered a health care provider as defined under HIPAA. However, we must have been informed of the provider's NPI, and it must have been loaded into our provider database. For claim status inquiry, NPI is required in the servicing provider field (it should be the same NPI that was submitted on the claim you are inquiring about), but the billing provider ID can be an NPI, Tax ID or PIN/PVN.

What should I do if I get an error message when I try to transmit my NPI in an eligibility, claim status inquiry, referral or precertification transaction?

In these instances, you should confirm that we have received and loaded your NPI into our database. You can confirm that your NPI is in our system by logging in to our secure provider website and selecting "Update Profiles." Then, select the NPI tab. Any NPIs you have submitted to Aetna that have been loaded into our database will be on the first screen.

How does NPI affect the referral inquiry and precertification inquiry transactions?

Although the referral inquiry and precertification inquiry transactions are not covered by the regulations, we can process them using the NPI as the provider identifier.

When authorization details are returned in response to these inquiries, the providers will be identified by an NPI, when an NPI is available in our database.

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