FAQs: USP Drug Classification System

1. Why is USP committed to this effort?

USP’s objective standards-setting process, longstanding experience in convening experts and stakeholders, and ability to leverage its work on other classification systems uniquely enables USP to lead this effort. This experience and commitment to existing formulary work intuitively aligns with USP’s mission to improve lives through public standards and related programs that help ensure the quality, safety, and benefit of medicines.

2. Why was the USP Drug Classification system created?

Stakeholder feedback indicated that the USP Medicare Model Guidelines (MMG) was being used beyond its intended use. The USP MMG was created specifically for Medicare Part D. Feedback highlighted the need to provide solutions to include prescriptions legally marketed beyond those specifically covered under the Medicare Part D benefit.

3. What type of feedback did USP receive that lead to the development of the USP Drug Classification System?

Stakeholders identified the following needs for a comprehensive classification system that:

  • Includes commercially available prescription drugs
  • Extends use beyond Medicare Part D
  • Tailors to specific stakeholder uses
  • Updates more frequently, at least yearly
  • Cross-references other systems
  • Makes use of new technologies
4. Through what forums did USP obtain feedback that lead to the development of the USP Drug Classification System?

USP has received feedback throughout the past 10 years. Examples include:

Public Comment on Medicare Model Guidelines (MMG) v6.0 (2013)

  • Participants included patient advocacy groups, manufacturers, and health plans.
  • Stakeholder requested categorization of drugs related to obesity and infertility.
  • However, comments were out of scope for MMG revision1

USP Stakeholder Meeting (2014)

  • Attendees included health plans, PBMs, MedPAC, and health policy analysts.
  • Stakeholder feedback identified short- and long-term opportunities.

Stakeholder Interviews (2015)

  • Interviews were conducted with health plans, PBMs, drug information knowledge vendors, and pharmacy consultants.
  • Stakeholders identified additional features and technology needs.
5. How will USP build off the successes and learning of the MMG?

The USP Drug Classification System is created by the same Expert Committee as the Medicare Model Guidelines and is developed with similar:

  • Guiding Principles
  • Taxonomy
  • Structure of the USP Categories and Classes
6. How is the USP Drug Classification System different than MMG?

The chart below details the differences. Highlights of the major differences include:

  • Independent USP/stakeholder model
  • Revised annually
  • Expanded drug placement beyond Medicare Part D eligible drugs in USP Categories and Classes
  • Involvement of all stakeholders in public comment period beyond Medicare Part D
  • Flexibility for additional features in the system (beyond USP Categories and Classes)

Proposed USP Drug Classification System Compared to USP MMG

  USP Medicare Model Guidelines(USP MMG) USP Drug Classification System (USP DC)
Developed through USP Volunteers, Stakeholder Engagement, and Public Comment Processes

Utilizes USP Guiding Principles for establishing Categories and Classes


Contains USP Categories and Classes


Provides Drug Examples Part D eligible drugs only Common US outpatient drugs

Implementation Tools: Mapping to RxNorm


CMS FRF- MMG Alignment File (triannual) USP DC- RxNorm Alignment File (annual)
Supports Medicare Part D requirements N/A
Stakeholder Focus in Public Comment Medicare Stakeholders All Stakeholders 
Revision Cycle Tri-annual* Annual
Publication Version USP MMG v7.0 Proposed first edition:
USP DC 2017
Publication Date February 1, 2017 February 1, 2017

*Upon request of CMS

7. Does the USP Drug Classification System include all drugs from MMG?

Yes, USP DC includes all drugs from MMG, along with a broader set of prescription medicines.

8. What sources were used to identify the drugs for the development of USP Drug Classification System?

Many different resources were utilized including RXNORM, FDA NDC File, CCIIO crosswalk, stakeholder feedback, commercial formularies, and the Purple Book.

9. What was the approach to creating new USP Categories or Classes for USP Drug Classification System?

The new USP Categories are created to encompass drugs that are included in commercial formularies beyond Medicare Part D. The new Categories created are Anti-obesity Agents, Infertility Agents, and Sexual Disorder Agents. The intended approach to creating new Categories or Classes is that they are broad enough to encompass future mechanism of actions and mindful of therapeutic options.

10. When will USP Drug Classification System be finalized?

The proposed publication date for the USP Drug Classification System is January 2018.