Buried in Section 6225 of the recently signed Consolidated Appropriations Act of 2026 is a small but mighty transparency provision: a unique national provider identifier (NPI) requirement. This measure has the potential to significantly improve the quality and usability of outpatient claims data; facilitate enforcement of site-neutral and other payment and competition laws; and, insurers maintain, enable them to negotiate and pay lower prices for hospital outpatient care. Nonetheless, work remains to be done to maximize the utility of this new measure, including ensuring it reaches the commercial market.
What Is A National Provider Identifier?
Under the Health Insurance Portability and Accountability Act (HIPAA) of 1996, all health care providers are required to acquire and use a 10-digit NPI on all standard transactions with public and private health care programs. Hospitals use organizational NPIs (which apply to a business entity), while health care professionals use individual NPIs (which apply to a single provider).
The Centers for Medicare and Medicaid Services (CMS), which oversees the registration of NPIs through the CMS National Plan and Provider Enumeration System (NPPES), often referred to as the National Provider System (NPS), does not limit the number of NPIs a health care provider may acquire. Hospitals may use different organizational NPIs for different payment programs or payer contracts, or may have inactive NPIs on file (for example, NPIs may be kept on file to keep complete patient records, even if they are no longer used). Historically, CMS has granted hospitals discretion as to whether to acquire distinct NPIs for different units or departments (technically subparts) that have a separate physical location or license. Some hospitals may use one NPI for all operations, while others could have dozens or more NPIs that they use for different purposes.
Why Are Unique National Provider Identifiers Needed?
Hospital outpatient claims, submitted on the UB-04 form or its electronic equivalent, must include an address and organizational NPI, but these can commonly correspond to the address of the hospital’s main campus or a billing office rather than the actual site of care. As hospitals have expanded their footprint, including through the acquisition of off-campus outpatient practices, payers and claims data analysts have lost sight of where care is actually being provided.
Not knowing the site of care is a significant barrier to understanding differences in payment across different sites and whether or not that variation is justifiable. For example, many outpatient facility fee bans and site-neutral payment reform proposals distinguish between on- and off-campus hospital outpatient departments (HOPDs); they often ban or reduce facility fees only for off-campus sites, but current commercial claims do not consistently convey this information. (This is in contrast to Medicare, in which providers must include modifiers on claims that distinguish whether care was provided on or off campus.) State laws banning antitiering or antisteering clauses that hospitals use to prohibit payers from directing patients toward particular, often lower-cost or higher-quality sites of care, may also have less of an effect if payers cannot differentiate separate outpatient settings within a hospital system in their claims.
Recognizing this information gap, states have begun enacting laws requiring that hospitals acquire and bill with a unique NPI for each off-campus location or otherwise clearly identify the place of care on claims.
What’s Required By The Newly Enacted Health Care Package?
Beginning January 1, 2028, hospitals must register for and bill with a unique NPI for each off-campus HOPD to receive payment under Medicare’s Outpatient Prospective Payment System (OPPS). Critical access hospitals, which receive cost-based reimbursement for outpatient care, are unaffected.
Covered hospitals will also be required to attest that they are complying with the unique NPI provision. One attestation is due before hospitals begin billing with their unique NPIs, and a second is due under a schedule CMS is to implement through notice and comment rulemaking. CMS also must use rulemaking to establish a review process for these attestations. The Office of Inspector General of the Department of Health and Human Services must report to Congress on the attestation review process by January 1, 2030.
Industry experts report that the process of obtaining an NPI is simple—perhaps a five-minute task. Likewise, updating billing systems to use the new NPI is simple. CMS regularly issues updated coding guidelines, and hospitals have staff in place to implement such changes. When interviewed for a 2023 report on outpatient facility fee reforms, informants in Colorado could not recall any complaints from hospitals describing a compliance burden related to the state’s 2018 unique NPI law.
What Effect Will This Have Outside Of Medicare?
It is unclear that this law will have any effect outside of the Medicare program, including on the commercial market. The new law does not impose any explicit requirements outside of Medicare’s OPPS. Many hospitals today may already use separate NPIs for Medicare versus commercial claims and seemingly could continue to do so under the new law.
In 2023, CMS issued guidance clarifying that payers could require each subpart of a health care provider, including each off-campus HOPD, to obtain a unique NPI. It is unclear whether payers have made such demands in their negotiations with hospitals and what the outcome has been if so. Large insurers and purchasers have been vocal advocates for a federal unique NPI requirement, suggesting they have not made significant headway demanding clarity in billing through private channels as things stand today.
How To Increase The Impact Of The New Unique National Provider Identifier Requirement
Policy makers will continue to scrutinize outpatient prices, use, and billing practices, and how these elements vary by site of service, in the coming years. Congress has given payers, regulators, and researchers a new tool to cast light on this site-based variation, but the view will remain cloudy without further action.
Federally, CMS can investigate whether it has authority under HIPAA to require hospitals to use the new location-specific, unique NPIs on commercial claims. Current regulations require that health care providers must use “the NPI it obtained from the NPS,” including an NPI for any subpart such as an HOPD, “to identify itself on all standard transactions that it conducts where its health care provider identifier is required.” Providers also must “disclose its NPI, when requested, to any entity that needs the NPI to identify that covered health care provider in a standard transaction.” These rules are ambiguous as to which NPI or combination of NPIs a hospital must use when it has multiple NPIs. CMS could clarify that providers must use and disclose the unique NPI of any subpart that has one, rather than any other NPI that applies to the broader entity, for all standard transactions.
CMS could also take this opportunity to revamp its NPPES database so that users can easily map the unique NPIs of any off-campus HOPDs (and other hospital subparts) to the hospital under whose license it is operating. While Medicare currently collects hospital NPIs on Medicare enrollment forms, many hospitals appear to report only the NPI(s) they use for billing Medicare. Additionally, when hospitals report multiple NPIs, the data are spread across multiple data sets making it cumbersome to patch together. For both payment and research purposes, it is critical to know both the specific outpatient location where care is provided and the hospital that operates the location.
To the extent CMS does not move on either front, states can stand in. As previously noted, multiple states have already enacted unique NPI requirements. The arguments against doing so have only diminished: States would not be imposing any burden on hospitals to acquire unique NPIs as the hospitals will already have to for Medicare (unless states seek to expand the requirements to critical access hospitals). States simply would have to require that hospitals use their new unique NPIs on commercial claims in addition to Medicare claims. States could also require that hospitals report their unique NPIs to the state health department or all-payer claims database for tracking purposes. Neither is a heavy lift, and such reporting could greatly enhance transparency into health care billing for outpatient services.
Author’s Note
The author is a faculty member of the Center on Health Insurance Reforms at Georgetown University’s McCourt School of Public Policy. Her time and research related to this article was supported by a grant from West Health. The author works on projects financially supported by Arnold Ventures and Blood Cancer United, in addition to West Health.
Christine Monahan “Unique National Provider Identifiers And A Push For Transparency” March 25, 2026, https://www.healthaffairs.org/content/forefront/unique-national-provider-identifiers-and-push-transparency. Copyright © 2026 Health Affairs by Project HOPE – The People-to-People Health Foundation, Inc.
