ICD-10-PCS 2027 procedure code
099C8ZXDrainage of Left Mastoid Sinus, Via Natural or Artificial Opening Endoscopic, Diagnostic
Short description: Drainage of Left Mastoid Sinus, Endo, Diagn
Code last changed in FY2018 (effective October 1, 2017). Source: official FY2027 ICD-10-PCS release from CMS. Page updated September 29, 2026. About our data
About 099C8ZX
099C8ZX is the ICD-10-PCS code for a drainage procedure on the left mastoid sinus using a via natural or artificial opening endoscopic approach (qualifier: diagnostic). In ICD-10-PCS, drainage means taking or letting out fluids and/or gases from a body part.
In plain terms, this corresponds to biopsy of middle and inner ear, the ICD-9-CM procedure title it maps to (20.32).
For a different body part, codes include 09938ZX (right external auditory canal), 09948ZX (left external auditory canal), 09958ZX (right middle ear), 09968ZX (left middle ear), 09978ZX (right tympanic membrane), 09988ZX (left tympanic membrane) and 20 more.
The same procedure with a different approach is coded 099C0ZX (open), 099C3ZX (percutaneous), 099C4ZX (percutaneous endoscopic) and 099C7ZX (via natural or artificial opening).
It doesn't appear in the MS-DRG procedure index, so on its own it doesn't change the DRG assignment.
It was added in FY2018, effective October 1, 2017.
What each character means
- 1. Section
- 0Medical and Surgical
- 2. Body System
- 9Ear, Nose, Sinus
- 3. Operation
- 9Drainage
Taking or letting out fluids and/or gases from a body part
The qualifier DIAGNOSTIC is used to identify drainage procedures that are biopsies
Includes: Thoracentesis, incision and drainage
- 4. Body Part
- CMastoid Sinus, Left
Includes: Mastoid air cells
- 5. Approach
- 8Via Natural or Artificial Opening Endoscopic
Entry of instrumentation through a natural or artificial external opening to reach and visualize the site of the procedure
- 6. Device
- ZNo Device
- 7. Qualifier
- XDiagnostic
Other versions of this procedure
Different body part
- 09938ZXExternal Auditory Canal, Right
- 09948ZXExternal Auditory Canal, Left
- 09958ZXMiddle Ear, Right
- 09968ZXMiddle Ear, Left
- 09978ZXTympanic Membrane, Right
- 09988ZXTympanic Membrane, Left
- 09998ZXAuditory Ossicle, Right
- 099A8ZXAuditory Ossicle, Left
- 099B8ZXMastoid Sinus, Right
- 099D8ZXInner Ear, Right
- 099E8ZXInner Ear, Left
- 099F8ZXEustachian Tube, Right
Different approach
Different qualifier
ICD-9-CM equivalent
Converter →- 20.32Biopsy of middle and inner earapproximate
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2018 (effective 10/1/2017): Added
- No changes since FY2018.
Common questions about 099C8ZX
Is 099C8ZX a valid ICD-10-PCS code for 2027?
- Yes. 099C8ZX is valid for inpatient procedures from October 1, 2026 through September 30, 2027.
What is the ICD-9 procedure code for 099C8ZX?
- The CMS GEMs map 099C8ZX to ICD-9-CM 20.32 (Biopsy of middle and inner ear).