The USP Drug Classification (USP DC) is an independent drug classification system developed in response to stakeholder input that it would be helpful to have a classification system beyond the Medicare Model Guidelines (MMG), to assist with formulary support outside of Medicare Part D. The Healthcare Safety & Quality Expert Committee goal is to create a comprehensive classification system for use in drug formulary development or review in non-acute or outpatient care settings. This tool has the potential to provide guidance towards the design and comparison of balanced formularies.
Important Updates
- December 15, 2023 – USP DC 2024 Intended Publication Date
- September 1 - 29, 2023 – USP DC 2024 Draft was available for Public Comment
- December 16, 2022: USP DC 2023 published
For additional information, please contact uspdc@usp.org
Please Note: The USP DC is not designed for CMS Part D Formulary Submissions. Part D Stakeholders should use the USP Medicare Model Guidelines (USP MMG)
Proposed Uses
The USP DC is intended for use by any stakeholder interested in a classification of drugs for use in formulary development or review. The classification system can have many uses for formulary support including but not limited to:
- Building and mapping formularies
- Reviewing formulary adequacy for a minimum baseline of drugs
- Identifying drugs in a particular pharmacologic grouping
- Reviewing formularies and comparing formulary design and benefits
USP DC may be helpful as part of a comprehensive formulary review process, but is not intended to replace the final review provided by the local pharmacy and therapeutics (P&T) committees. Moreover, USP DC is not intended for review of medical benefit drug coverage, since USP DC does not include all drugs administered in a clinical setting.
Origins of Development
USP has a long history of creating classification systems for the purpose of formulary review. USP has developed and updated the USP Medicare Model Guidelines since 2004, under the Medicare Prescription Drug Improvement and Modernization Act (2003), Section 1860D-4(b)(3)(C)(ii). This section included a requirement that Part D plans cover at least two drugs in each USP Category and Class.
The USP DC was initiated by stakeholder feedback to meet evolving public health needs. Over the past ten years, the USP MMG has been adopted in other health policy settings outside of its intended Medicare utilization. USP has received public comments and stakeholder feedback that identified the need to create an independent classification system to provide a more comprehensive inclusion of outpatient drugs, more frequent revisions, and more detailed mapping tools for implementation.
The USP DC is a classification system separate from the MMG and is not endorsed or funded by the CMS.
Comparison to the MMG
A comparison of the USP DC to the MMG
| USP Medicare Model Guidelines (USP MMG) | USP Drug Classification (USP DC) | |
|---|---|---|
| Developed under the Medicare Modernization Act to support Medicare Part D requirements |
√ |
N/A |
|
Provides Drug Examples
|
Part D eligible drugs only | Common US outpatient drugs |
| Developed through USP Expert Volunteers, Stakeholder Engagement, and Public Comment Processes | √ | √ |
|
Utilizes USP Guiding Principles for establishing Categories and Classes
|
√ | √ |
| Implementation Tools: Mapping to RxNorm | CMS FRF- MMG Alignment File (triennial) | USP DC- RxNorm Alignment File (annual) |
| Stakeholder Focus in Public Comment | Medicare Stakeholders | All Stakeholders |
| Revision Cycle | Every 3 years* | Annual |
| Current Publication Version | USP MMG v9.0 | USP DC 2023 |
| Intended Publication Date |
September 29, 2023 |
December 16, 2022 |
*Upon request of Centers for Medicare and Medicaid Services (CMS)
Organization of USP DC 2023
The USP DC 2023 contains a listing of single entity drug products, combination drug products, and vaccines.
Below is a definition of the data elements on the USP Drug Classification.
| Data Element | USP DC 2023 | Definition |
|---|---|---|
| USP Category | 50 Categories | A USP Category is the broadest classification of the USP Drug Classification system and provides a high level formulary structure. |
| USP Class | 172 Classes | A USP Class is a more granular classification, occurring within a specific USP Category in the USP Drug Classification system. |
| Pharmacotherapeutic Group | 315 Pharmacotherapeutic Groups |
An attribute of a drug, providing additional informational groupings on drugs based on therapeutic use or pharmacology. The pharmacotherapeutic groups are currently under development and not intended to be used for review of formulary adequacy for a minimum baseline of drugs. |
| Example Drug | 1961 Example Drugs | An example drug is the active ingredient in a drug product (not an inactive ingredient, such as an excipient). An example drug includes the active ingredient of a drug product but not its strength or dosage form. |
| Filter by Type |
Users can filter only this column to choose to select/view any of the following data elements: USP Category, USP Class, USP Pharmacotherapeutic group, a combination drug product, or a single entity drug product. (Cat)- USP Category |
USP DC Development Process
The USP DC is developed through USP’s independent, science-based, expert-led process that relies on stakeholder input, including formal public comment periods.
USP Drug Classification Expert Volunteers
The USP Drug Classification was created by an Expert Panel during the 2015-2020 cycle formed under the Healthcare Safety and Quality Expert Committee. For the 2020-2025 cycle, a new USP Drug Classification Subcommittee was formed to continue the work. The Subcommittee consists of academicians, practitioners, formulary experts, patient advocates, and clinicians. This Subcommittee advises the Healthcare Safety and Quality Expert Committee on issues discovered during the annual revision processes that are relevant to developing, implementing, and revising the USP DC.
Drug Identification
Drugs included in the USP DC 2023 are identified through various sources including:
- Drugs@FDA
- RxNorm Current Prescribable Content
- Purple book: Lists of Licensed Biological Products
- Stakeholder feedback, and publicly available prescription formularies
Guiding Principles
As with the 2022 version, the USP Drug Classification Subcommittee used the following guiding principles to inform their development of the USP DC 2023.
The subcommittee is comprised of academicians, practitioners, formulary experts, patient advocates, and clinicians. They advise the Healthcare Safety & Quality (HSQ) Expert Committee on issues discovered during the annual revision processes that are relevant to developing, implementing, and revising the USP DC.
Types of Example Drugs Listed
The Subcommittee's goal was to include a comprehensive list of drugs used in non-acute and outpatient care settings. This includes prescription medications patients receive from community pharmacies, specialty pharmacies, skilled nursing facilities, and infusion centers. At this time, the Subcommittee has excluded from the USP DC 2023 most medications used in hospital-only settings, over-the-counter drugs, and medications that are not FDA-approved. Some listed drugs may have over-the-counter products as well as prescription-only dosage forms. For example, diphenhydramine is available as an over-the-counter product for oral dosage forms and prescription-only for injectable dosage forms.
Approach to creating Categories and Classes
The USP Drug Classification retains the guiding principle of the Medicare Model Guidelines (MMG), to strike a balance of assuring patient access to the drugs that patients need with the flexibility that health plans require in offering an affordable and effective benefit.
When creating the categories and classes, there was careful consideration to minimize the creation of categories or classes with less than three drug examples.
Approach to Placement of Example Drugs
The USP DC utilizes pharmacotherapeutic evidence within the context of FDA-approved indications for placing example drugs. Many of these example drugs may have established indications and uses outside of the United States and qualities of other drug classes (pharmacology). A drug in the associated list may appear in more than one USP Category or USP Class if there is a scientifically valid and clinically meaningful patient care use.
Combination products are placed in USP groupings distinguished by "Combinations" or "Other" under the respective USP Category. If the combination product includes an active ingredient that improves absorption or efficacy of another active ingredient, the placement will be based on the active ingredient that contributes to therapy and not the augmenting agent. For example, Amoxicillin/Clavulanate Potassium is placed in USP Class "Beta-lactam, Penicillins" based on amoxicillin and not clavulanate potassium, an augmenting agent that enhances the spectrum of activity of amoxicillin by inhibiting beta-lactamases that inactivate amoxicillin.
Specific dosage forms/formulations/delivery systems are generally not listed but may be included in the associated list if there is a valid and clinically meaningful patient care issue addressed by these more specific factors.
Versions of USP Drug Classification
USP Drug Classification 2023
(published December 16, 2022)
USP Drug Classification 2022
(published December 17, 2021)
• Download USP Drug Classification 2022
USP Drug Classification 2021
(published December 18, 2020)