K61.1 Rectal abscess

The ICD-10-CM code for Rectal abscess is K61.1 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

11: Diseases of the digestive system (K00-K95)

Section

K55-K64: Other diseases of intestines (K55-K64)

Category K61

9 codes (7 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to K61.1:

• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › pararectal
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › perirectal
• Cellulitis (diffuse) (phlegmonous) (septic) (suppurative) › rectum
• Cellulitis (diffuse) (phlegmonous) (septic) (suppurative) › perirectal
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › rectum
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › intestine, intestinal NEC › rectal

Inclusion Terms

• Perirectal abscess

U.S. Hospital Utilization

• An estimated 24,820 U.S. inpatient stays in 2023 included K61.1 among the documented diagnoses.
• 8,255 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Chapter 11 reserved for future expansion

11. Chapter 11: Diseases of the Digestive System (K00-K95) Reserved for future guideline expansion

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)