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Inpatient Procedure Code

0N9400Z

Drainage of Left Parietal Bone with Drainage Device, Open Approach

Drainage of Left Parietal Bone with Drain Dev, Open Approach

Axis Breakdown

Every ICD-10-PCS code is exactly seven characters, one per axis. Each character's meaning is defined by its position in the code.

PositionValueMeaning
1
Section0

Medical and Surgical

2
Body SystemN

Head and Facial Bones

3
Root Operation9

Drainage

Taking or letting out fluids and/or gases from a body part

4
Body Part4

Parietal Bone, Left

5
Approach0

Open

6
Device0

Drainage Device

7
QualifierZ

No Qualifier

Potential MS-DRG Relationships (FY2026)

The MS-DRG grouper treats this as an operating room procedure. It appears in the surgical logic of 6 MS-DRGs:

  • MDC 01 — Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis: DRG 023, DRG 024
  • MDC 01 — Craniotomy and endovascular intracranial procedures: DRG 025, DRG 026, DRG 027
  • MDC 24 — Craniotomy for Multiple Significant Trauma: DRG 955

From the CMS MS-DRG Definitions Manual, Appendix E. Actual DRG assignment depends on the complete claim.

Contextual Map

Every relationship of 0N9400Z in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

PCS table

  • 0N9[PCS table]
  • [object Object] — Section: [object Object] [Section]: “[object Object]”
  • [object Object] — Body System: [object Object] [Body System]: “[object Object]”
  • [object Object] — Operation: [object Object] [Operation]: “[object Object]”

MS-DRG participation

  • DRG 023 — CRANIOTOMY WITH MAJOR DEVICE IMPLANT OR ACUTE COMPLEX CNS PRINCIPAL DIAGNOSIS WITH MCC OR ANTINEOPLASTIC IMPLANT OR EPILEPSY WITH NEUROSTIMULATOR [MS-DRG]: “CRANIOTOMY WITH MAJOR DEVICE IMPLANT OR ACUTE COMPLEX CNS PRINCIPAL DIAGNOSIS WITH MCC OR ANTINEOPLASTIC IMPLANT OR EPILEPSY WITH NEUROSTIMULATOR — Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis (MDC 01)”
  • DRG 024 — CRANIOTOMY WITH MAJOR DEVICE IMPLANT OR ACUTE COMPLEX CNS PRINCIPAL DIAGNOSIS WITHOUT MCC [MS-DRG]: “CRANIOTOMY WITH MAJOR DEVICE IMPLANT OR ACUTE COMPLEX CNS PRINCIPAL DIAGNOSIS WITHOUT MCC — Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis (MDC 01)”
  • DRG 025 — CRANIOTOMY AND ENDOVASCULAR INTRACRANIAL PROCEDURES WITH MCC [MS-DRG]: “CRANIOTOMY AND ENDOVASCULAR INTRACRANIAL PROCEDURES WITH MCC — Craniotomy and endovascular intracranial procedures (MDC 01)”
  • DRG 026 — CRANIOTOMY AND ENDOVASCULAR INTRACRANIAL PROCEDURES WITH CC [MS-DRG]: “CRANIOTOMY AND ENDOVASCULAR INTRACRANIAL PROCEDURES WITH CC — Craniotomy and endovascular intracranial procedures (MDC 01)”
  • DRG 027 — CRANIOTOMY AND ENDOVASCULAR INTRACRANIAL PROCEDURES WITHOUT CC/MCC [MS-DRG]: “CRANIOTOMY AND ENDOVASCULAR INTRACRANIAL PROCEDURES WITHOUT CC/MCC — Craniotomy and endovascular intracranial procedures (MDC 01)”
  • DRG 955 — CRANIOTOMY FOR MULTIPLE SIGNIFICANT TRAUMA [MS-DRG]: “CRANIOTOMY FOR MULTIPLE SIGNIFICANT TRAUMA — Craniotomy for Multiple Significant Trauma (MDC 24)”

MDC crossing · diagnoses (11364)

  • MDC 01 — Diseases and Disorders of the Nervous System [MDC crossing]: “Diseases and Disorders of the Nervous System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”
  • MDC 24 — Multiple Significant Trauma [MDC crossing]: “Multiple Significant Trauma — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”
  • A02.21 — Salmonella meningitis [Same-MDC diagnosis]: “Salmonella meningitis — grouped in MDC 01, the diagnosis side of this code's crossing.” · check together
  • A06.6 — Amebic brain abscess [Same-MDC diagnosis]: “Amebic brain abscess — grouped in MDC 01, the diagnosis side of this code's crossing.” · check together
  • A17.0 — Tuberculous meningitis [Same-MDC diagnosis]: “Tuberculous meningitis — grouped in MDC 01, the diagnosis side of this code's crossing.” · check together
  • A17.1 — Meningeal tuberculoma [Same-MDC diagnosis]: “Meningeal tuberculoma — grouped in MDC 01, the diagnosis side of this code's crossing.” · check together
  • A17.81 — Tuberculoma of brain and spinal cord [Same-MDC diagnosis]: “Tuberculoma of brain and spinal cord — grouped in MDC 01, the diagnosis side of this code's crossing.” · check together
  • and 11359 more

Nearest codes

  • 0N9000Z — Drainage of Skull with Drainage Device, Open Approach [One axis away]
  • 0N9100Z — Drainage of Frontal Bone with Drainage Device, Open Approach [One axis away]
  • 0N9300Z — Drainage of Right Parietal Bone with Drainage Device, Open Approach [One axis away]
  • 0N940ZZ — Drainage of Left Parietal Bone, Open Approach [One axis away]
  • 0N9430Z — Drainage of Left Parietal Bone with Drainage Device, Percutaneous Approach [One axis away]
  • 0N9440Z — Drainage of Left Parietal Bone with Drainage Device, Percutaneous Endoscopic Approach [One axis away]
  • 0N9500Z — Drainage of Right Temporal Bone with Drainage Device, Open Approach [One axis away]
  • 0N9600Z — Drainage of Left Temporal Bone with Drainage Device, Open Approach [One axis away]

Change history

No changes recorded for this code — unchanged since the FY2026 (April) baseline of the change ledger.