LMHCPCS Level II

Left main coronary artery

Usage notes
Append to cardiac catheterization/intervention codes to identify the left main coronary artery as the vessel treated.
Common mistakes
Reporting LM for a left circumflex or left anterior descending intervention — the left main is a distinct, more proximal vessel.

Related modifiers

Frequently asked questions

What does modifier LM mean?

Left main coronary artery

When do I use modifier LM?

Append to cardiac catheterization/intervention codes to identify the left main coronary artery as the vessel treated.

What's a common mistake with modifier LM?

Reporting LM for a left circumflex or left anterior descending intervention — the left main is a distinct, more proximal vessel.

HCPCS modifier data from CMS. CPT® is a registered trademark of the American Medical Association — CPT modifier descriptions are not included on this site. Always verify codes with authoritative sources before making billing decisions.