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ICD-10-CM 2027

ICD-10 code for Fissural cyst

K09.1

Developmental (nonodontogenic) cysts of oral region

✓ Billable / specific

From the official ICD-10-CM alphabetic index entry “Cyst (colloid) (mucous) (simple) (retention) › fissural (oral region)”. Page updated September 29, 2026.

About coding Fissural cyst

The ICD-10-CM code for Fissural cyst is K09.1 (Developmental (nonodontogenic) cysts of oral region).

Within K09 (cysts of oral region, not elsewhere classified), K09.1 is specifically for developmental (nonodontogenic) cysts of oral region. Related codes cover developmental odontogenic cysts (K09.0), other cysts of oral region, not elsewhere classified (K09.8) and cyst of oral region, unspecified (K09.9).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), DRG 157 (Dental and Oral Diseases with MCC, relative weight 1.809), DRG 158 (Dental and Oral Diseases with CC, relative weight 0.9366) and DRG 159 (Dental and Oral Diseases without CC/MCC, relative weight 0.6893), in Pre-MDC and MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

Common questions about Fissural cyst ICD-10 codes

What is the ICD-10 code for Fissural cyst?

K09.1 — Developmental (nonodontogenic) cysts of oral region.

Is K09.1 billable?

Yes. K09.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can K09.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict K09.1 as a principal diagnosis.

Is K09.1 a CC or MCC?

No. K09.1 is neither a CC nor an MCC under MS-DRG v44.0.