The United States Pharmacopeia Drug Classification (USP DC) 2026, released on January 29, incorporates structural revisions to categories, classes, and pharmacotherapeutic groups, and adds Food and Drug Administration-approved products through October 2025 for non-Part D health plan formulary guidance.

The USP is a nonprofit organization that disseminates public compendial quality standards for medicines and maintains two drug classification systems: the Medicare Model Guidelines (MMG) for Part D plans and the DC for non-Part D plans. These classification systems group eligible drugs into categories and classes that health plans can use in their formulary development process. While there are limited formal requirements regarding how health plans interact with the USP’s classification systems, the USP’s decisions on how drugs are grouped have downstream impacts on plan formularies, coverage requirements, and patient access.

As proposed in December 2025, the USP’s classification systems would also be used to identify drugs eligible for participation in the Global Benchmark for Efficient Drug Pricing (GLOBE) and Guarding U.S. Medicare Against Rising Drug Costs (GUARD) Models, which would apply international reference pricing requirements to a subset of Medicare drug utilization.

The USP Releases Two Classification Sets to Guide Formulary Development

The Medicare Prescription Drug Improvement and Modernization Act of 2003 requires the USP, in collaboration with stakeholders, to create a list of categories and classes for Medicare Part D drug formulary development. The Centers for Medicaid & Medicare Services (CMS) contracts with USP to draft the MMG for this purpose; the USP typically updates drugs and classifications on a three-year schedule.

At the request of health plans with other books of business (i.e., non-Medicare Part D plans), the USP launched the first version of the DC in 2019. The DC includes medications beyond those specifically covered under the Part D benefit (e.g., medical benefit products, cough and cold medicines, fertility therapies) and is more comprehensive than the MMG. Unlike the three-year update cycle of the MMG, the DC is updated annually, offering stakeholders more opportunities to engage the USP. In addition, the USP DC includes a third level of granularity to drug classification, Pharmacotherapeutic Groups (PGs), which offers additional opportunity for differentiation.

Updates to the USP DC

New Categories: One new category: “Kidney agents” with the following classes: angiotensin II receptor antagonists, angiotensin-converting enzyme inhibitors, GLP-1 receptor agonists, HMG CoA reductase inhibitors, mineralocorticoid receptor antagonists, sodium-glucose co-transporter 2 inhibitors.

New Classes: Two new classes: “Disease modifying agents” in the Antidementia agents category and “Antivirals, RSV agents” in the Antivirals category.

New Pharmacotherapeutic Groups (PGs): Four new PGs in the “Antineoplastics” category: “Menin inhibitors”, “Multitargeted kinase inhibitors, ROS1”, “Anti-C-met antibodies”, and “Anti-VEGF antibodies.”

Changed Classes and PGs:

• One class renamed: “Analgesics combinations” in Analgesics category was renamed to “Analgesics combinations/other.”
• Three PGs renamed: “Epidermal growth factor receptor inhibitors” was renamed to “inhibitors”; “Multitargeted kinase inhibitors, CSF1R, KIT, FLT3”, was renamed to “Multitargeted kinase inhibitors, CSF1R”; and “Anti-PD1 antibodies” was renamed to “Anti-PD1/PDL1 antibodies.”

Removed PGs: No PGs were removed in this update.

Added/Removed Products: 115 products were added and 12 products were removed.

Upcoming Updates to the Medicare Model Guidelines

Work on MMG v10.0 is anticipated to begin this year, with the draft expected to be posted for public comment in June and finalized in fall 2026. Given that Part D formularies must be submitted to CMS by the first Monday in June for the subsequent plan year, Avalere Health expects MMG v9.0 to be effective through Plan Year (PY) 2027 and MMG v10.0 to be effective from PY 2028 to 2030.

Figure 1. Timelines for Recent and Upcoming USP MMG and DC Updates

Applicability of USP Classifications to Most Favored Nations Pricing Demonstrations

The proposed GLOBE and GUARD Models each define the drugs subject to model participation based on USP classifications. The GLOBE Model, for Medicare Part B, would include drugs from seven USP DC categories.¹ The GUARD Model, for Medicare Part D, would include drugs from 17 USP MMG categories.² Each model includes additional components (e.g., Medicare spending thresholds) in its inclusion criteria; however, this would be a new and meaningful use of USP’s classifications.

Drug manufacturers, and particularly those with new pharmacy benefit products or indications since September 2023, may wish to engage USP this June on the draft MMG v10.0 to inform their MMG placement. For any products or indications approved since fall 2025, manufacturers should also consider engagement for the draft USP DC 2027 this fall.

Collaborate with Avalere Health for Strategic USP Support

Avalere Health can support your team in analyzing USP classification updates for your products, identifying strategic opportunities, and influencing future editions of the USP DC and USP MMG. Our subject matter experts are also here to assist your team in understanding any impact of the final USP DC and USP MMG on the recently released GLOBE and GUARD Models.

Avalere Health’s experts in prescription drugs and formulary systems support clients in analyzing USP classification updates, identifying strategic opportunities, and influencing future editions of the USP Drug Classification. We partner with clients to ensure classifications reflect current medical practices and enhance patient access to therapies.

To learn more about how Avalere can support your engagement with the USP, connect with us.

¹ USP DC categories for GLOBE eligibility include: antigout agents, antineoplastics, blood products and modifiers, central nervous system agents, immunological agents, metabolic bone disease agents, and ophthalmic agents.

² USP MMG categories for GUARD eligibility include: analgesics; anticonvulsants; antidepressants; antimigraine agents; antineoplastics; antipsychotics; antivirals; bipolar agents; blood glucose regulators; cardiovascular agents; central nervous system agents; gastrointestinal agents; genetic or enzyme or protein disorder: replacement or modifiers or treatment; immunological agents; metabolic bone disease agents; ophthalmic agents; and respiratory tract/pulmonary agents.