JK HCPCS Level II modifier: One month supply or less of drug or biological

JK is a HCPCS Level II modifier: “One month supply or less of drug or biological.” It adds this detail to the code it is reported with.

Official description

JK

One month supply or less of drug or biological

Short description: Drug supply 1 month or less

HCPCS · United States

Medicare details

The indicators CMS publishes with JK in its October 2026 file. They describe Medicare’s handling, not another payer’s.

Medicare coverage
Carrier judgment
Added
Apr 1, 2023

Where JK sits

  1. 1GroupHCPCS modifiers
  2. 2Modifier JKOne month supply or less of drug or biological

Source and release

Data release
HCPCS Level II · October 2026
Effective date
Oct 1, 2026
Publisher
CMS

This page is built from the HCPCS Level II catalog that Vero Codes reads when it suggests codes: Centers for Medicare & Medicaid Services’s October 2026 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.

Frequently asked questions

What does HCPCS code JK mean?

JK is the HCPCS code for “One month supply or less of drug or biological” in CMS’s HCPCS Level II October 2026 release.

Where is JK in the HCPCS Level II list?

JK is listed under Modifiers.

Does Medicare cover JK?

CMS lists JK’s Medicare coverage as “Carrier judgment”. Coverage and payment still depend on the patient, the setting, the documentation and the payer.

Which HCPCS Level II release does this page use?

It uses CMS’s October 2026 release, in effect from Oct 1, 2026 to Dec 31, 2026. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.