USP Drug Classification

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 published 
  • September 1 - 29, 2023 – USP DC 2024 Draft was available for Public Comment

For additional information, please contact

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)

Updates to the USP DC 2024

The USP Drug Classification (USP DC 2024) will be published on December 15, 2023, and can be downloaded by completing a short form. This year, the freely accessible version of the USP DC will only include a list of FDA-approved example drugs outside of Medicare Part D, organized by categories and classes. 

USP Drug Classification PLUS

On December 15, 2023, the drug classification file that includes coded identifiers (previously known as the Drug Alignment File) will be introduced as part of a new, subscription-based offering: USP Drug Classification PLUS available on the USP Store. USP DC PLUS will include additional information to support your classification review of newly approved FDA drugs used in outpatient settings.

  USP Drug Classification 2024 USP Drug Classification PLUS
Location USP DC Webpage USP DC PLUS Webpage
Access Free Subscription
Requirements Form Completion (e.g., name, e-mail, intended use) USP Access Point account (e.g., Tax ID, Customer ID)
Content Classification of a list of FDA-approved example drugs outside of Medicare Part D that are organized by Categories and Classes.

Classification of a list of FDA-approved example drugs outside of Medicare Part D that are organized by Categories and Classes, PLUS:

  • An interactive tool for product and pricing comparison
  • Access to NDC codes to connect with product and pricing information
  • Access to RxNorm Concept Unique Identifiers (RxCUIs)
Format Excel File
  1. Web-based zip file (AKA: Content Cloud)
  2. Browser interface (AKA: Viewpoint)

For additional information, please visit the USP DC PLUS Page to learn more.

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

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) N/A
Stakeholder Focus in Public Comment Medicare Stakeholders All Stakeholders 
Revision Cycle Every 3 years* Annual
Current Publication Version USP MMG v9.0 USP DC 2024
Publication Date

September 29, 2023

December 15, 2023

 *Upon request of Centers for Medicare and Medicaid Services (CMS) 

Organization of USP DC 2024

The USP DC 2024 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 2024 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 174 Classes A USP Class is a more granular classification, occurring within a specific USP Category in the USP Drug Classification system. 
Pharmacotherapeutic Group 129 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 1991 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
(Class)- USP Class
(PG)- USP Pharmacotherapeutic Group
(min)- The example drug is multi-ingredient and contains more than 1 active ingredient
(in)- The drug contains only 1 active ingredient


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 2024 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 2023 version, the USP Drug Classification Subcommittee used the following guiding principles to inform their development of the USP DC 2024.

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 2024 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

Through the lens of equity and diversity, when appropriate, the USP DC will consider issues such as genomic status, medical conditions, race, ethnicity, disability, sexual orientation, or gender identity in drug classification.

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 2024

(published December 15, 2023)

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)

•    Download USP Drug Classification 2021