20.21 - Incision Of Mastoid

The ICD 9 Code for Incision of mastoid is listed as 20.21.
Additional information concerning this code and description can be found below including ICD 10 crosswalks / GEMS and chapter information where available.

ICD 9 CM Volume 3 (PCS) Field	Value
Procedure Code:	20.21
Description:	Incision of mastoid
Short Description:	Mastoid incision

Chapter:	Operations on the ear
Subsection 1:	Other operations on middle and inner ear
ICD-10-PCS General Equivalence Mappings (GEMS):
ICD 10 PCS Code:	099B00Z - Drainage of Right Mastoid Sinus with Drainage Device, Open Approach (approximate)
ICD 10 PCS Code:	099B0ZZ - Drainage of Right Mastoid Sinus, Open Approach (approximate)
ICD 10 PCS Code:	099B30Z - Drainage of Right Mastoid Sinus with Drainage Device, Percutaneous Approach (approximate)
ICD 10 PCS Code:	099B3ZZ - Drainage of Right Mastoid Sinus, Percutaneous Approach (approximate)
ICD 10 PCS Code:	099B40Z - Drainage of Right Mastoid Sinus with Drainage Device, Percutaneous Endoscopic Approach (approximate)
ICD 10 PCS Code:	099B4ZZ - Drainage of Right Mastoid Sinus, Percutaneous Endoscopic Approach (approximate)
ICD 10 PCS Code:	099C00Z - Drainage of Left Mastoid Sinus with Drainage Device, Open Approach (approximate)
ICD 10 PCS Code:	099C0ZZ - Drainage of Left Mastoid Sinus, Open Approach (approximate)
ICD 10 PCS Code:	099C30Z - Drainage of Left Mastoid Sinus with Drainage Device, Percutaneous Approach (approximate)
ICD 10 PCS Code:	099C3ZZ - Drainage of Left Mastoid Sinus, Percutaneous Approach (approximate)
ICD 10 PCS Code:	099C40Z - Drainage of Left Mastoid Sinus with Drainage Device, Percutaneous Endoscopic Approach (approximate)
ICD 10 PCS Code:	099C4ZZ - Drainage of Left Mastoid Sinus, Percutaneous Endoscopic Approach (approximate)
ICD-9-CM Volume 3 (PCS) Siblings (same level / similar specificity) of 20.21:
20.22 - Incision of petrous pyramid air cells
20.23 - Incision of middle ear