Standard Unique Health Identifier for Healthcare Providers

3. NPI Standard

Proposed Provisions (§ 142.402(a))

The May 7, 1998, proposed rule (at 63 FR 25328) described our proposal for the standard health care provider identifier. We proposed the NPI standard as an 8-position alphanumeric identifier. It would include as the 8th position a numeric check digit to assist in identifying erroneous or invalid NPIs. The check digit would be a recognized International Standards Organization (ISO) standard. The check digit algorithm would be computed from an all-numeric base number. Therefore, any alpha characters that may be part of the NPI would be translated to a specific numeric before the calculation of the check digit. The NPI format would allow for the creation of approximately 20 billion unique identifiers. It would be an intelligence-free identifier. In the May 7, 1998 proposed rule, we also proposed the type of data included in the file containing identifying information for each health care provider.

In addition to the description of the NPI standard, this section of the May 7, 1998, proposed rule discussed several other points on which we received comments:

We noted that we proposed the 8- position alphanumeric format rather than a longer numeric-only format in order to keep the identifier as short as possible while providing for an identifier pool that would serve the industry’s needs for a long time.

We listed selection criteria for the standard and discussed candidate identifiers, including the National Association of Boards of Pharmacy number, the Social Security Number, and the Employer Identification Number.

We noted that the USA Registration Committee approved the NPI as an International Standards Organization card issuer identifier in August 1996 for use on standard health identification cards.

Comments and Responses on the NPI Standard

Comment: Several commenters on the format of the NPI expressed general support for our proposal or specific support for an 8-position alphanumeric identifier. Very few of these commenters gave a reason for support of the 8- position alphanumeric format. A strong majority of commenters recommended instead that the NPI be a 10-position numeric identifier, because a 10- position identifier would yield an adequate pool of identifiers and would not exceed the length permitted for identifiers in the standard transactions proposed under HIPAA. A few other commenters recommended a 9-position numeric identifier. Several commenters who favored a numeric identifier stated that if additional capacity for NPIs were needed in the future, additional numeric digits should be added at that time. Commenters who preferred a numeric identifier were very specific in listing its advantages. They stated that a numeric identifier—

• Is more quickly and accurately keyed in data-entry applications;
  
• Is more easily used in telephone keypad applications;
  
• Does not require translation before application of the check digit algorithm,

and thus uses the full ability of the check digit algorithm to detect keying errors;

• Is compatible with ISO identification card standards for a card issuer identifier (discussed below), while an alphanumeric identifier is not; and


• Will require less change for systems that currently use a numeric identifier.

Response: We find the stated advantages of a 10-position numeric identifier convincing. We have revised
proposed § 142.402 (now § 162.406(a)) to provide that the NPI will be a 10- position numeric identifier, with the 10th position being an ISO standard check digit. The use of a 10-digit numeric NPI and our initial assignment strategy will allow for 200 million unique NPIs. We estimate 200 million NPIs would last approximately 200 years, allowing for health care provider growth, as discussed later in the preamble of this final rule in section V.D., ‘‘Specific Impact of the NPI.’’ If additional capacity for NPIs is needed in the future, additional numeric digits will be added to the identifier at that time. A modification to the NPI format would be accomplished through rulemaking. A 10-position numeric identifier is specified in § 162.406(a).

Comment: Some commenters asked that we clarify how the NPI would appear when used as a card issuer identifier on a standard health care identification card. Commenters also asked that we clarify any modification made to the check digit algorithm to allow the NPI to be used as a card issuer identifier.

Response: In December 1997, an American National Standard for a Uniform Healthcare Identification Card was approved by the National Committee for Information Technology Standards (NCITS), which is a standards-developing organization accredited by the American National Standards Institute. The specification for this standard, NCITS.284, is available from the American National Standards Institute, 11 West 42nd Street, New York, New York 10036. One identifier field on the standard health care identification card is the card issuer identifier. A card issuer identifier is an identifier for an entity that issues a health care dentification card. In most cases, the entity issuing a health care identification card would be a health plan; in some cases, however, the entity could be a health care provider. We note that, under HIPAA, health care providers are neither required to issue health care identification cards, nor to use the NCITS.284 standard card. The NCITS.284 standard requires that the first five digits of the card issuer identifier be ‘‘80840,’’ where the initial two digits, 80, signify health applications, the next three digits, 840, signify United States. The remainder of the card issuer identifier identifies the entity that issued the card. In August 1996, the USA Registration Committee, a standards-developing organization accredited by the American National Standards Institute, approved the NPI as an identifier for a card issuer for use on a standard health care identification card. If the NPI is used to identify the card issuer on a card that complies with NCITS.284, the card issuer identifier would consist of 15 positions as follows:‘‘80840,’’ signifying health applications in the United States, followed by the 10-position NPI (the 9-position identifier portion of the NPI, followed by the NPI check digit).

We note that the initial five digits‘‘80840’’ would be required with the NPI only when the NPI is used as a card issuer identifier on a standard health care identification card. However, in order that any NPI could potentially be used as a component of the card issuer identifier on a standard health care identification card, the NPI check digit calculation must always be performed as though the NPI is preceded by‘‘80840.’’ This is easily accomplished by including a constant in the check digit calculation when the NPI is used without this prefix. The NPI check digit is calculated using the ISO standard Luhn check digit algorithm, a modulus 10 ‘‘double-add-double’’ algorithm. The specification for calculation of the NPI check digit will be made available on the CMS Web site (http:// www.cms.hhs.gov). The specification will explain how to compute the check digit and how to verify an NPI using the check digit, both when the ‘‘80840’’ prefix is present and when it is not.

Comment: A strong majority of commenters supported our proposal that the NPI be intelligence-free. A few commenters stated that an intelligence-free identifier would not meet their needs because their systems use the facility provider type, which is coded as part of the identifier in some current systems.

Response: If the NPI were to include intelligence, that is, coded information about the health care provider, as part of the identifier, a new NPI would have to be issued any time the coded information about the health care provider changed. This would undermine the lasting nature of the NPI. For this reason we agree with the large majority of commenters that the NPI not contain intelligence about the health care provider.

Comment: A small number of commenters stated that the Taxpayer Identifying Number (TIN) should be selected, or reconsidered, as the standard unique health identifier for health care providers.

Response: The TIN is the identifier under which the health care provider reports a United States tax return to the Internal Revenue Service (IRS). It can be an SSN, assigned by the Social Security Administration, or an IRS Individual Taxpayer Identification Number (ITIN), assigned by the IRS, or an EIN, assigned by the IRS. A large number of commenters on the ‘‘Data’’ section of the May 7, 1998, NPI proposed rule stated their opposition to dissemination of the SSN except in strictly controlled situations that fully comply with the Privacy Act. Use of the SSN or the TIN as the standard unique health identifier for health care providers would require the wide dissemination and use of the SSN or TIN in the HIPAA transactions under conditions that would not be protected by the Privacy Act. The majority of commenters did not support the use of the SSN as the standard unique health identifier for health care providers for individuals.

Comment: The National Council for Prescription Drug Programs requested that we make several clarifications regarding our reference to the National Association of Boards of Pharmacy (NABP) number, which we discussed as a candidate identifier in the May 7, 1998, proposed rule.

Response: As requested, we note that the NABP number has been renamed the National Council for Prescription Drug Programs (NCPDP) Provider Number. In 1997, the NCPDP and the NABP mutually severed the contract made in 1977. The NCPDP has full responsibility for maintenance of the pharmacy file. The NCPDP Provider Number is issued solely by NCPDP. All references to the NABP number should be changed instead to the NCPDP Provider Number.

Comment: A small number of commenters stated that the proposed NPI would not meet one or more of the selection criteria for standards or would not be consistent with the law because it would not reduce the administrative costs of providing and paying for health care. These kinds of comments cited the high costs of developing and operating a new system for health care provider enumeration.

Response: Elsewhere in this preamble, we discuss how the collection of health care provider data and the enumeration of health care providers can be satisfactorily accomplished with the NPI and how those associated costs can be kept to a minimum. We acknowledge that organizations will incur costs in the
move to a standard enumeration process. After the initial implementation, however, we believe that the costs will diminish significantly, and that long-term use of a standard identifier will be cost-effective.

Final Provisions (§ 162.406(a))

We are adopting the NPI format of an all-numeric identifier, 10 positions in length, with an ISO standard check-digit in the 10th position (§ 162.406(a)). The NPI will not contain intelligence about the health care provider. This format and our assignment strategy will allow for at least 200 million unique NPIs.

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