P4 HCPCS Level II modifier: A patient with severe systemic disease that is a constant threat to life
P4 is a HCPCS Level II modifier: “A patient with severe systemic disease that is a constant threat to life.” It adds this detail to the code it is reported with.
Official description
P4A patient with severe systemic disease that is a constant threat to life
Short description: Pt w/sev sys dis threat life
HCPCS · United States
Medicare details
The indicators CMS publishes with P4 in its October 2026 file. They describe Medicare’s handling, not another payer’s.
- Medicare coverage
- Carrier judgment
- Added
- Jan 1, 2006
Where P4 sits
- 1GroupHCPCS modifiers
- 2Modifier P4A patient with severe systemic disease that is a constant threat to life
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 P4 mean?
P4 is the HCPCS code for “A patient with severe systemic disease that is a constant threat to life” in CMS’s HCPCS Level II October 2026 release.
Where is P4 in the HCPCS Level II list?
P4 is listed under Modifiers.
Does Medicare cover P4?
CMS lists P4’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.
Codes beside P4
All modifiersNBNebulizer system, any type, fda-cleared for use with specific drugNRNew when rented (use the 'nr' modifier when dme which was new at the time of rental is subsequently purchased)NUNew equipmentP1A normal healthy patientP2A patient with mild systemic diseaseP3A patient with severe systemic diseaseP5A moribund patient who is not expected to survive without the operationP6A declared brain-dead patient whose organs are being removed for donor purposesPASurgical or other invasive procedure on wrong body partPBSurgical or other invasive procedure on wrong patientPCWrong surgery or other invasive procedure on patientPDDiagnostic or related non diagnostic item or service provided in a wholly owned or operated entity to a patient who is admitted as an inpatient within 3 days