K09.9 Cyst of oral region, unspecified

Billable ICD-10-CM code, FY2026.

Applies from K09 Cysts of oral region, not elsewhere classified

Includes

• lesions showing histological features both of aneurysmal cyst and of another fibro-osseous lesion

Excludes2 (not included here)

• cysts of jaw (M27.0-, M27.4-)
• radicular cyst (K04.8)

MS-DRG index

Defines the logic of DRG(s) 011-013 in MDC PRE.

Approximate ICD-9-CM (GEMs)

• 528.4 Cysts of oral soft tissues (approximate)

Code annotations containing back-references to K09.9

Back-references to K09

• Type 2 Excludes: K13 Other diseases of lip and oral mucosa ("cysts of oral region (K09.-)")
• Type 1 Excludes: M27.4 Other and unspecified cysts of jaw ("cysts of oral region (K09.-)")

Diagnosis Index entries for K09.9

• Cyst (colloid) (mucous) (simple) (retention) › oral › region
• Cyst (colloid) (mucous) (simple) (retention) › oral › soft tissue

Nearby codes

• K09 Cysts of oral region, not elsewhere classified
• K09.0 Developmental odontogenic cysts
• K09.1 Developmental (nonodontogenic) cysts of oral region
• K09.8 Other cysts of oral region, not elsewhere classified
• K09.9 Cyst of oral region, unspecified (this code)