K1 HCPCS Level II modifier: Lower extremity prosthesis functional level 1 - has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed…

K1 is a HCPCS Level II modifier: “Lower extremity prosthesis functional level 1 - has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed cadence. typical of the limited and unlimited….” It adds this detail to the code it is reported with.

Official description

K1

Lower extremity prosthesis functional level 1 - has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed cadence. typical of the limited and unlimited household ambulator.

Short description: Lwr ext prost functnl lvl 1

HCPCS · United States

Medicare details

The indicators CMS publishes with K1 in its October 2026 file. They describe Medicare’s handling, not another payer’s.

Medicare coverage: Carrier judgment
Added: Jan 1, 1993

Where K1 sits

1GroupHCPCS modifiers
2Modifier K1Lower extremity prosthesis functional level 1 - has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed cadence. typical of the limited and unlimited household ambulator.

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.

See K1 in the CMS source

Frequently asked questions

What does HCPCS code K1 mean?

K1 is the HCPCS code for “Lower extremity prosthesis functional level 1 - has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed cadence. typical of the limited and unlimited household ambulator.” in CMS’s HCPCS Level II October 2026 release.

Where is K1 in the HCPCS Level II list?

K1 is listed under Modifiers.

Does Medicare cover K1?

CMS lists K1’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.

All modifiers

JGDrug or biological acquired with 340b drug pricing program discount, reported for informational purposes JKOne month supply or less of drug or biological JLThree month supply of drug or biological JWDrug amount discarded/not administered to any patient JZZero drug amount discarded/not administered to any patient K0Lower extremity prosthesis functional level 0 - does not have the ability or potential to ambulate or transfer safely with or without assistance and a prosthesis does not enhance…K2Lower extremity prosthesis functional level 2 - has the ability or potential for ambulation with the ability to traverse low level environmental barriers such as curbs, stairs or…K3Lower extremity prosthesis functional level 3 - has the ability or potential for ambulation with variable cadence. typical of the community ambulator who has the ability to…K4Lower extremity prosthesis functional level 4 - has the ability or potential for prosthetic ambulation that exceeds the basic ambulation skills, exhibiting high impact, stress…KAAdd on option/accessory for wheelchair KBBeneficiary requested upgrade for abn, more than 4 modifiers identified on claim KCReplacement of special power wheelchair interface