2027 ICD-10-CM Diagnosis Code Q43.6Congenital fistula of rectum and anus

ICD-10-CM Codes›Q00-Q99›Q38-Q45›Q43

ICD-10-CM Q43.6
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Q43.6 is a billable ICD-10-CM diagnosis code for congenital fistula of rectum and anus. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 393 through 395. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 21 closely related codes. The code is exempt from POA reporting. Coders also document this condition as anorectal fistula. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Digestive congenital anomalies.

Code Identity

ICD-10-CM Code
Q43.6
Billable Status
Yes — Valid for Submission
Code Describes
Congenital fistula of rectum and anus
Short Description
Congenital fistula of rectum and anus
Same as the full description in the CMS dataset.
Parent Code
Q43
Other congenital malformations of intestine

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ38-Q45Other congenital malformations of the digestive system
CategoryQ43Other congenital malformations of intestine
This CodeQ43.6Congenital fistula of rectum and anus

Present on Admission (POA)Billing

Q43.6 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Other congenital malformations of the digestive system (Q38-Q45).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Anorectal fistula
  • Congenital anoperineal fistula
  • Congenital anorectal fistula due to high anorectal malformation
  • Congenital anorectal fistula due to intermediate anorectal malformation
  • Congenital anorectal fistula due to low anorectal malformation
  • Congenital fecal fistula
  • Congenital fistula of anus
  • Congenital fistula of rectum
  • Congenital fistula of rectum and anus
  • Enterocutaneous fistula

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Q43.6: its own notes plus those printed at Chapter 17. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • congenital fistula of anus with absence, atresia and stenosis (Q42.2)
  • congenital fistula of rectum with absence, atresia and stenosis (Q42.0)
  • congenital rectovaginal fistula (Q52.2)
  • congenital urethrorectal fistula (Q64.73)
  • pilonidal fistula or sinus (L05.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • inborn errors of metabolism (E70-E88)

Notes

General instructions on how these codes are used.

From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • Codes from this chapter are not for use on maternal records

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name Q43.6, its category, or a range that includes it.

Excludes1 3

These codes carry an Excludes1 note naming Q43.6: they are not reported together with it, unless the two conditions are unrelated.

  • K60.3 Anal fistula
    congenital fistula (Q43.6)
  • K60.4 Rectal fistula
    congenital fistula (Q43.6)
  • K60.5 Anorectal fistula
    congenital fistula (Q43.6)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MAL002
Digestive congenital anomalies
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Anal Disorders

Your anus is the opening at the end of your large intestine. It is where stool (poop) leaves your body.

The full article covers:

  • What is the anus?
  • What are anal disorders?
  • What are the symptoms of anal disorders?
  • How are anal disorders diagnosed?
  • How are anal disorders treated?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert Q43.6 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
751.5 Intestinal anomaly NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Q43.6Overview

What is the ICD-10 code for congenital fistula of rectum and anus?

The ICD-10-CM code for congenital fistula of rectum and anus is Q43.6 (sometimes written as Q436). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is Q43.6 (Other congenital malformations of intestine) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report congenital fistula of rectum and anus on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does Q43.6 group to?

When congenital fistula of rectum and anus is the principal diagnosis on an inpatient stay, it groups to MS-DRG 394, 395, 393, with relative weights from 0.6379 to 1.5877 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q43.6 a CC or MCC?

CMS lists Q43.6 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 21 closely related codes in its exclusion list.

Is Q43.6 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for congenital fistula of rectum and anus on inpatient claims. The code appears in the Other congenital malformations of the digestive system (Q38-Q45) range of the CMS exempt list.