ICD-10 Code O70.4: Anal sphincter tear complicating delivery

Key Takeaways

ICD-10 code O70.4 is a billable ICD-10-CM diagnosis code for anal sphincter tear complicating delivery, not associated with third degree laceration, valid for FY2026.

The official ‘Applicable To’ inclusion note for O70.4 is: perineal laceration, rupture or tear during delivery, as in O70.1, also involving sphincter NOS.

O70.4 applies only when there is no accompanying third-degree laceration — per its own Excludes1 note, a sphincter tear with a third degree perineal laceration is coded to O70.2- instead.

Practice management software like Pabau helps obstetric teams document sphincter involvement accurately, supporting correct O70.4 assignment and clean claims submissions.

ICD-10 code O70.4 is a billable ICD-10-CM diagnosis code for an anal sphincter tear complicating delivery that is not associated with a third-degree perineal laceration. It sits within the O70 perineal laceration category, and applies when the operative or delivery note documents sphincter involvement without an accompanying third-degree laceration.

ICD-10 code O70.4: Quick reference and billable status

According to the Centers for Medicare and Medicaid Services (CMS), ICD-10 code O70.4 is confirmed billable for FY2024, FY2025, and FY2026. The table below captures the essential reference data coders need at a glance.

What O70.4 means: Clinical description and how it’s distinguished

ICD-10 code O70.4 represents an anal sphincter tear that occurs as a direct complication of delivery and is not associated with a third-degree perineal laceration.

The code carries its own Excludes1 note that makes the distinction explicit: an anal sphincter tear occurring together with a third-degree perineal laceration is excluded from O70.4 and instead codes to O70.2- (third degree perineal laceration during delivery).

That absence of an accompanying third-degree laceration is the deciding factor for O70.4, not the extent of rectal mucosal involvement.

Clinically, these injuries are grouped under the term obstetric anal sphincter injuries (OASI). An OASI involves the external anal sphincter, the internal anal sphincter, or both. The degree of involvement determines which O70 code is correct, making provider documentation of sphincter layer involvement essential for accurate coding.

The code’s official “Applicable To” note ties O70.4 back to O70.1: it applies to a perineal laceration, rupture, or tear during delivery — the same clinical event described at O70.1 (second degree perineal laceration) — that also involves the anal sphincter, without a specified degree of involvement and without an accompanying third-degree laceration.

Coders using the patient record to review the delivery and repair notes together can confirm whether that sphincter involvement is documented before assigning O70.4.

Applicable-to note for ICD-10 code O70.4

The ICD-10-CM tabular list includes one official “Applicable To” inclusion note under O70.4, verified against AAPC’s ICD-10-CM code reference.

“Perineal laceration, rupture or tear during delivery, as in O70.1, also involving sphincter NOS.” This is the single official inclusion note under O70.4: it ties the code to the same clinical event captured at O70.1 (second degree perineal laceration) when the anal sphincter is also involved, without a specified degree of involvement and without an accompanying third-degree laceration.

When the operative or delivery note documents sphincter involvement without an accompanying third-degree laceration, O70.4 is the correct code assignment.

The alphabetic index path Laceration, perineum, complicating delivery leads coders to this code via the sphincter ani subentry, so provider language in the operative record directly controls the coding outcome.

The O70 perineal laceration category: All sibling codes

ICD-10 code O70.4 belongs to the O70 perineal laceration during delivery category. Understanding where it sits relative to its sibling codes prevents misassignment. The CDC/NCHS ICD-10-CM web tool confirms the following structure for O70, current for FY2026.

O70.9 is the code of last resort when documentation is genuinely insufficient to assign any other code. Coders should query the provider before defaulting to unspecified; for obstetric documentation workflows, structured forms that capture sphincter layer involvement at the time of delivery prevent these unspecified assignments.

How ICD-10 code O70.4 differs from third and fourth-degree lacerations

The most common coding error with O70.4 is interchanging it with O70.2x or O70.3 without reviewing the clinical documentation. The distinction is clinically defined and directly affects code assignment. Here is the decision framework coders can apply at the time of chart review.

When the operative record documents a sphincter tear but does not confirm a third-degree perineal laceration, ICD-10 code O70.4 is the correct assignment. Per its own Excludes1 note, O70.4 cannot be reported when a third-degree laceration is also documented for the same delivery — that combination codes to O70.2-, not O70.4.

Clinics using digital intake forms for obstetric encounters can build sphincter-layer checkboxes directly into delivery documentation templates, reducing ambiguity at the point of care rather than at the coding desk.

Excludes1 and excludes2 notes for O70.4

The O70 category carries coding restriction notes that apply across the subcategory, including O70.4. Coders should review these before finalizing the claim.

Excludes1 notes (cannot be coded together)

The O70 category Excludes1 notes specify conditions that should never be coded alongside any O70 subcategory code. Excludes1 means the condition is included in another code, and the two codes cannot appear together.

• O70 category Excludes1: obstetric high vaginal laceration alone (code to O71.4)
• O70.4 Excludes1 (code-specific): anal sphincter tear with third degree perineal laceration (code to O70.2-)

The O70.4-level Excludes1 note is the one that matters most for correct code assignment: it confirms that a sphincter tear documented alongside a third-degree perineal laceration is never coded as O70.4. In that scenario, the encounter codes to the appropriate O70.2- subcategory instead.

Code also note

The O70 category carries a “Code Also” note instructing coders to additionally report any perineal laceration repair procedure that was performed, using the applicable ICD-10-PCS procedure code, whenever a repair is documented in the operative note.

This is a diagnosis-to-procedure cross-reference. It tells coders to capture the repair itself as a separate procedure code, distinct from the delivery-outcome sequencing guidance covered in the coding guidelines below.

For claims management workflows, this means the encounter claim should carry O70.4 alongside the repair procedure code whenever a repair was performed and documented.

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Coding guidelines and documentation requirements for O70.4

The ICD-10-CM Official Guidelines for Coding and Reporting govern how O70.4 is assigned and sequenced. The following rules apply to obstetric laceration coding in the context of this code, consistent with the WHO’s ICD-10 classification framework and CMS guidance.

1. Code after delivery outcome: Obstetric complication codes from Chapter 15 require a code for the delivery outcome (Z37.x) on the same claim. O70.4 is a complication code, not a standalone delivery code.
2. Sequencing as additional diagnosis: O70.4 typically sequences as an additional diagnosis on inpatient claims when the principal reason for admission was delivery. It may sequence as the principal diagnosis in specific outpatient settings when a patient presents for management of the sphincter injury itself.
3. POA exempt: Obstetric codes in the O00-O9A chapter are generally present-on-admission exempt. Coders should verify against the current CMS POA exempt list annually, as this list is updated with each fiscal year’s IPPS final rule.
4. Documentation required: The operative or delivery note must document the anal sphincter involvement. “Perineal laceration” alone does not support O70.4; the sphincter must be specifically identified as involved.
5. MS-DRG impact: O70.4 may affect DRG assignment when coded as a complication on inpatient claims. Review the current IPPS final rule for the relevant DRG groupings, as MS-DRG assignments are subject to annual revision.

For practices managing pelvic floor and postpartum complications, a system built for pelvic health documentation can embed delivery complication checklists directly into postpartum note templates, so sphincter layer information reaches the coding team without a separate provider query step.

Pabau’s AI medical scribe can help structure dictated delivery notes into discrete documentation fields, capturing the clinical detail ICD-10 code O70.4 requires.

Alphabetic index references for O70.4

The ICD-10-CM alphabetic index provides several entry paths that lead coders to O70.4. Knowing these paths reduces the risk of landing on an unspecified or incorrect sibling code.

• Laceration, perineum, complicating delivery, sphincter ani leads to O70.4
• Tear, perineum, complicating delivery, sphincter leads to O70.4
• Injury, obstetric, anal sphincter leads to the O70 category, with O70.4 assigned when the sphincter tear does not also involve a third-degree laceration

Delivery complications often cluster on the same claim, so coders should also check whether the encounter involves O66.5, which shares the same O60-O77 block as O70.4.

How Pabau supports obstetric coding and documentation accuracy

Accurate assignment of ICD-10 code O70.4 depends on provider documentation capturing the right clinical detail at delivery. Most coding errors in the O70 category trace back to delivery notes that describe the injury in general terms without specifying sphincter layer involvement. Fixing that starts at the point of care, before the chart ever reaches the coding desk.

Pabau supports OB/GYN and women’s health practices with structured digital clinical forms that can be built to include complication-specific fields: sphincter involvement type, degree classification, repair method, and outcome notes.

When providers complete these structured fields at the point of care, the coding team receives the precise language needed to assign codes like O70.4 on the first review, without queries or delays.

Pabau’s client record system keeps delivery documentation, prior obstetric history, and repair records in a single linked view, which is particularly relevant for confirming whether a third-degree laceration was also present at the same delivery.

Coders reviewing the delivery and repair notes together can quickly confirm whether the operative record documents an accompanying third-degree laceration, which determines whether the current encounter codes to O70.4 or to O70.2- instead.

For practices running HIPAA-compliant documentation workflows, Pabau’s access controls and audit trails support the compliance requirements that obstetric records carry.

Conclusion

ICD-10 code O70.4 is a precisely scoped billable code for anal sphincter tears that occur during delivery without an accompanying third-degree perineal laceration. Per its own Excludes1 note, a sphincter tear that occurs together with a third-degree laceration is excluded from O70.4 and codes to O70.2- instead.

Accurate assignment requires provider documentation that specifies sphincter involvement and confirms whether a third-degree laceration was also present.

For OB/GYN practices that want to tighten the link between delivery documentation and clean coding, Pabau’s structured forms and clinical record tools help ensure delivery notes capture the sphincter-involvement detail O70.4 requires. Book a demo to see how Pabau supports obstetric documentation workflows from the delivery room to the claim.

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