K56.609: Unspecified intestinal obstruction, unspecified as to partial versus complete obstruction

The ICD-10-CM code for a mechanical intestinal obstruction when the record establishes neither the underlying cause nor whether the obstruction is partial or complete.

Billable

FY2027

TABLE OF CONTENTS

Example H2

Medical scribe app interface showing a recording waveform, a list of patient notes, and a SOAP note for John Doe.

Stop looking up codes.

Scribe auto-generates them for you.

Try Commure Scribe →

At a glance

Code Family

K56: Paralytic ileus and intestinal obstruction without hernia.

Condition

Intestinal obstruction

Billable

Yes, valid for HIPAA-covered transactions.

DRG Grouping

MS-DRG 388, 389 or 390 under the FY2027 MS-DRG v44 grouper, depending on complications and comorbidities.

HCC Mapping (v28)

HCC 78: Intestinal Obstruction/Perforation, superseded by HCC 77 when that also applies. Every billable code in category K56 maps to it.

Family Specificity

Subcategory K56.60 splits on whether the obstruction is documented as partial or complete, with K56.609 as the residual code when the degree is not stated.

Which K56 code do I assign?

Category K56 splits first on the mechanism and the documented cause of the obstruction, then on whether the obstruction is partial or complete. Reserve K56.609 for a mechanical obstruction where the record establishes neither the cause nor the degree.

When documentation says…

Code

Small bowel obstruction, cause and degree not stated

K56.609

A mechanical intestinal obstruction with neither a documented cause nor a documented degree. The note must record the obstruction as a working or confirmed diagnosis, and it must not identify adhesions, a hernia, volvulus, intussusception or a gallstone as the cause.

Partial small bowel obstruction on CT

K56.600

A partial intestinal obstruction of unspecified cause. The imaging, operative or endoscopic findings must characterize the obstruction as partial.

Complete obstruction, no cause identified

K56.601

A complete intestinal obstruction of unspecified cause. The record must characterize the obstruction as complete.

Obstruction due to adhesions found at laparotomy

K56.50

Intestinal adhesions with obstruction, degree not stated. When adhesions are the documented cause, the adhesion code is assigned in place of K56.609.

Adynamic ileus, no mechanical obstruction

K56.0

Paralytic ileus, a non-mechanical failure of peristalsis. The provider must distinguish adynamic ileus from mechanical obstruction. K56.609 covers mechanical obstruction only.

Bowel obstruction following recent abdominal surgery

K91.30

Postprocedural intestinal obstruction, degree not stated. An obstruction documented as a complication of a prior procedure is reported from the K91.3- range, which category K56 excludes.

Tabular notes

EXCLUDES1

Category K56 excludes congenital stricture or stenosis of intestine (Q41–Q42), cystic fibrosis with meconium ileus (E84.11), ischemic stricture of intestine (K55.1), meconium ileus NOS (P76.0), neonatal intestinal obstructions classifiable to P76.-, obstruction of duodenum (K31.5) and postprocedural intestinal obstruction (the K91.3 codes). An Excludes1 note means the excluded condition is not reported with a K56 code for the same condition.

EXCLUDES2

Category K56 carries an Excludes2 note for stenosis of anus or rectum (K62.4). An Excludes2 note permits dual coding when both conditions are documented.

FY2027: EFFECTIVE 1 OCTOBER 2026

K56.609 is valid in the FY2026 code set and unchanged in the FY2027 update, which took effect on 1 October 2026. The FY2027 code and tabular addenda add, delete or revise nothing in category K56. K56.609 carries no tabular-level Use Additional, Code First or Code Also instruction.

Operational & financial impact

Why specificity matters beyond the chart: risk adjustment, DRG assignment and denial exposure all follow from which code is selected.

CMS-HCC v28 (PY2024+)

K56.609 maps to CMS-HCC v28 category HCC 78: Intestinal Obstruction/Perforation. HCC 77, Intestine Transplant Status/Complications, sits above it in the same hierarchy and supersedes it when both apply to the same patient.

Under CMS-HCC v24 it mapped to HCC 33, Intestinal Obstruction/Perforation. The v24 to v28 transition keeps the code in a payment category.

All 16 billable codes in category K56 map to HCC 78. Recording the obstruction as partial or complete does not change the category. Code the causative condition whenever it is identified.

MS-DRG v44 (FY2027)

MS-DRG 388: gastrointestinal obstruction with MCC.

MS-DRG 389: gastrointestinal obstruction with CC.

MS-DRG 390: gastrointestinal obstruction without CC or MCC.

K56.609 as a principal inpatient diagnosis groups under MDC 06, diseases and disorders of the digestive system, in the FY2027 MS-DRG v44 grouper. Placement across the three tiers depends on the complication and comorbidity codes present on the full claim.

Medicare and commercial payers

Medicare: K56.609 is a valid billable code. Inpatient reimbursement is governed by MS-DRG 388 through 390.

WHERE SPECIFICITY IS LOST

K56.609 is the residual code of subcategory K56.60. It reports neither the cause nor the degree of the obstruction.

When imaging, operative or endoscopic findings establish the degree, K56.600 for a partial obstruction or K56.601 for a complete obstruction carries the greater specificity.

When the cause is established, the causative code replaces K56.609. Adhesions direct the encounter to the K56.5- codes, volvulus to K56.2, intussusception to K56.1, and a hernia with obstruction to the K40–K46 hernia categories.

Documentation checklist to support K56.609

Chart elements that support code selection and reduce specificity-driven denials.

A documented diagnosis of intestinal obstruction, recorded as either the working or the confirmed diagnosis.

Documentation that the obstruction is mechanical rather than adynamic. Paralytic ileus is reported with K56.0 instead.

The absence of a documented specific cause. If adhesions, a hernia, volvulus, intussusception or a gallstone is identified, the specific causative code is assigned in place of K56.609.

The absence of a documented degree. If the record states partial or complete, assign K56.600 or K56.601.

The imaging, operative and endoscopic reports available at the time of coding, reviewed for any statement of the degree of obstruction.

Any prior abdominal or pelvic procedure. An obstruction documented as a complication of that procedure is reported from the K91.3- range.

The management provided, such as nasogastric decompression, bowel rest, intravenous fluids or surgical exploration.

For an inpatient stay, a review of the postoperative findings, which may support a more specific code such as one of the K56.5- adhesion codes.

FAQ

Is K56.609 a billable code?

Yes. K56.609 is valid for HIPAA-covered transactions. It is the residual sixth-character code within subcategory K56.60, used when the degree of obstruction is not documented.

When should I use K56.609 instead of K56.600 or K56.601?

Use K56.609 when the documentation does not state whether the obstruction is partial or complete. Use K56.600 when the record characterizes the obstruction as partial. Use K56.601 when the record characterizes it as complete. Assign the most specific code the provider documentation supports.

Does K56.609 map to an HCC?

Yes. K56.609 maps to HCC 78: Intestinal Obstruction/Perforation under CMS-HCC v28. Under CMS-HCC v24 it mapped to HCC 33, also titled Intestinal Obstruction/Perforation. Every billable code in category K56 maps to HCC 78. Recording the obstruction as partial or complete does not change the category.

What is the difference between K56.609 and K56.0?

K56.609 reports a mechanical obstruction, meaning a physical barrier to the passage of intestinal contents. K56.0 reports paralytic ileus, an adynamic failure of peristalsis with no mechanical barrier. The distinction is drawn from the provider documentation.

What do I assign when surgery identifies adhesions as the cause?

Assign the adhesion code in place of K56.609. K56.50 covers intestinal adhesions with obstruction when the degree is not stated, K56.51 covers partial obstruction, and K56.52 covers complete obstruction. K56.609 is a code of last resort, used only when the cause is not established.

How does K56.609 group for inpatient payment?

As a principal diagnosis, K56.609 groups under MDC 06 in the FY2027 MS-DRG v44 grouper. The three tiers are MS-DRG 388 with MCC, MS-DRG 389 with CC, and MS-DRG 390 without CC or MCC. The tier depends on the complication and comorbidity codes reported on the claim.

Can K56.609 be reported in the outpatient setting?

Yes. K56.609 may be reported for an emergency department or urgent care evaluation where obstruction is documented but not yet fully characterized. If the patient is admitted from that encounter, the inpatient coding rules govern the admission.

Did K56.609 change for FY2027?

No. K56.609 is unchanged in the FY2027 update, effective 1 October 2026, which adds, deletes or revises nothing in category K56. No FY2026 changes were identified for K56.609 or for the parent K56.6 subcategory. The code and the family structure are stable for the year beginning October 1, 2025.

Related codes

Codes in the same family as K56.609. Only codes with a published page render as links.

Sibling codes in the K56 family

K56.0: Paralytic ileus.
K56.1: Intussusception.
K56.2: Volvulus.
K56.3: Gallstone ileus.
K56.41: Fecal impaction.
K56.49: Other impaction of intestine.
K56.50: Intestinal adhesions [bands], unspecified as to partial versus complete obstruction.
K56.51: Intestinal adhesions [bands], with partial obstruction.
K56.52: Intestinal adhesions [bands] with complete obstruction.
K56.600: Partial intestinal obstruction, unspecified as to cause.
K56.601: Complete intestinal obstruction, unspecified as to cause.
K56.690: Other partial intestinal obstruction.
K56.691: Other complete intestinal obstruction.
K56.699: Other intestinal obstruction unspecified as to partial versus complete obstruction.
K56.7: Ileus, unspecified.

Additional codes to consider

Codes outside the K56 family considered alongside K56.609.

Consider instead

K56.600: Partial intestinal obstruction, unspecified as to cause, where the record documents a partial obstruction.
K56.601: Complete intestinal obstruction, unspecified as to cause, where the record documents a complete obstruction.
K56.0: Paralytic ileus, where the obstruction is adynamic rather than mechanical.
K56.50: Intestinal adhesions [bands], unspecified as to partial versus complete obstruction, where adhesions are the documented cause.
K56.2: Volvulus, where volvulus is the documented cause.
K56.1: Intussusception, where intussusception is the documented cause.
K91.30: Postprocedural intestinal obstruction, unspecified as to partial versus complete, where the obstruction follows a prior procedure.
K40–K46: Hernia categories, where a hernia with obstruction is documented.
K31.5: Obstruction of duodenum, which category K56 excludes.
K55.1: Chronic vascular disorders of intestine, where an ischemic stricture of the intestine is documented.
K62.4: Stenosis of anus and rectum.

Sources

All claims on this page derive from government and professional-standards sources.

National Center for Health Statistics. (2026). International classification of diseases, tenth revision, clinical modification (ICD-10-CM) FY2027 files. https://www.cdc.gov/nchs/icd/icd-10-cm/files.html
Centers for Medicare & Medicaid Services and National Center for Health Statistics. (2026). ICD-10-CM official guidelines for coding and reporting FY2027. https://ftp.cdc.gov/pub/Health_Statistics/NCHS/Publications/ICD10CM/2027/ICD-10-CM-October-1-2026-FY27-Guidelines.pdf
Centers for Medicare & Medicaid Services. (2025). 2026 model software/ICD-10 mappings. https://www.cms.gov/medicare/payment/medicare-advantage-rates-statistics/risk-adjustment/2026-model-software-icd-10-mappings
Centers for Medicare & Medicaid Services. (2026). MS-DRG classifications and software, version 44. https://www.cms.gov/medicare/payment/prospective-payment-systems/acute-inpatient-pps/ms-drg-classifications-and-software