ICD code T87.43 – Right lower extremity amputation stump infection

ICD-10 Code T87.43: Infection of amputation stump, right lower extremity is a billable ICD-10-CM code, valid for FY2026 HIPAA-covered transactions. It took effect on October 1, 2025 under the CDC/NCHS ICD-10-CM FY2026 release.

Assign it when the record documents an infected amputation stump on the right leg. It is one of five billable codes under T87.4, and laterality is what separates them. Amputation level does not change it. A below-knee stump and an above-knee stump on the right side both code to T87.43.

Key takeaways

T87.43 is the billable ICD-10-CM code for an infected amputation stump on the right lower extremity, effective October 1, 2025.

Parent code T87.4 has five billable children, T87.40 through T87.44, and laterality is what separates them.

The chart must name the side and state infection, because redness or swelling alone will not support T87.43.

Amputation level does not change the code, so below-knee and above-knee right stumps both code to T87.43.

Practice management software like Pabau validates ICD-10 codes before submission, so a laterality error surfaces before the payer sees it.

Code hierarchy: T87.4 and its five billable codes

Parent code T87.4 covers amputation stump infection at any site. Five billable child codes sit under it, and each one names a site and a side. The common error in this family is the left-for-right swap between T87.43 and T87.44.

T87.4 itself is a header code and is never billable. A claim carrying T87.4 alone comes back rejected as insufficiently specific. Assign one of the five child codes above instead, based on the site and side in the record. Where the record names no side, T87.40 is the correct fallback.

How laterality decides which T87.4 code applies

Laterality decides the code, and the chart decides the laterality. When the record says only “stump infection”, the coder has to fall back to T87.40. That assignment is correct, though many payers follow it with a request for records.

Use this framework before assigning any T87.4x code:

“Right lower extremity” covers below-knee and above-knee stumps alike. The code does not differentiate by amputation level. A transtibial stump infection on the right side codes to T87.43, and so does a transfemoral one.

Coding guidelines and documentation requirements

The ICD-10-CM Official Guidelines for Coding and Reporting govern how T87.43 is assigned. The includes notes, the excludes notes, and the checklist below cover the three denial patterns this code attracts.

Includes notes

T87.43 includes post-procedural wound infection of the amputation stump. A stump wound that becomes infected after the original amputation belongs here. The infection is a sequela of the procedure rather than a separate primary condition.

Excludes notes

T87.43 carries no formal Excludes 1 or Excludes 2 note at the code level. Cellulitis of the lower limb is still a separate condition from stump infection. Where the provider describes cellulitis of the residual limb, L03.115 fits the right side better. Query the provider when the chart reads ambiguously between the two.

Documentation checklist

• Laterality confirmed. The record states right leg, right lower extremity, or right lower limb, not just “lower extremity”.
• Infection documented. The provider writes “infected”, “infection”, or “infected wound”. Redness, swelling, or warmth alone does not establish infection.
• Stump identified. The site is the amputation stump residual limb, not a separate wound on an intact limb.
• Causative organism, where known. Record it for secondary coding, such as Staphylococcus aureus.
• Validity window. T87.43 holds for HIPAA-covered transactions through September 30, 2026, the end of FY2026.

Those three requirements fail in predictable ways, so it helps to see the wording side by side.

Documentation has to support the code before the claim goes out, not after a denial lands. Querying the provider during the encounter, or right after it, costs far less time than appealing later.

Clinical indicators that support the code

An amputation stump infection is bacterial invasion of residual limb tissue after surgical amputation. It is a post-procedural complication, separate from cellulitis of an intact limb. Peripheral arterial disease and diabetic foot complications drive most lower-limb amputations in the US, so wound care and vascular teams meet these stumps often.

Indicators that support T87.43 include erythema spreading beyond the wound edge, purulent discharge, local warmth, fever, a raised white cell count, and positive wound cultures. The provider has to document these findings. A coder cannot infer infection from a list of signs without a provider statement.

• Common organisms: Staphylococcus aureus (including MRSA), Pseudomonas aeruginosa, and mixed anaerobes in diabetic patients
• Amputation levels captured: transtibial (below-knee), transfemoral (above-knee), and hip disarticulation, all on the right side
• Typical care setting: post-acute wound care, vascular surgery follow-up, or readmission for debridement
• Where it shows up: vascular surgery, orthopedic surgery, wound care billing, and hospital inpatient coding

Structured note templates help wound care teams capture these findings at the point of care. The wording lands in the chart during the visit, so the coder rarely has to query it afterwards.

Related ICD-10 codes and crosswalk reference

Coders in wound care, vascular surgery, and orthopedics meet the codes next to T87.43 often. The table below maps the ones most often confused with it. Our ICD-10-CM code index covers the neighboring codes in this chapter.

T87.43 and T87.5x are not mutually exclusive. Where the chart documents both infection and necrosis of the same right stump, assign both codes. Sequence them by the condition chiefly responsible for the encounter.

How Pabau helps coders get T87.43 right

Wound care and vascular practices billing T87.43 need the laterality question settled before a claim leaves the building.

Practice management software like Pabau gives coders a workflow for billing teams that validates ICD-10 codes through the Claim.MD clearinghouse before submission. A claim missing laterality, or one coded to T87.40 by default, gets flagged at validation rather than returned as a denial weeks later.

Pabau also carries structured clinical note templates for the provider. They prompt for site, side, and infection wording while the patient is still in the room. That capture feeds the billing workflow, so coders chase fewer queries after the encounter. For electronic claims, Pabau supports the 837P format and electronic remittance advice through Claim.MD.

The built-in ICD-10 catalog makes it quicker to find T87.43 next to its siblings, without switching reference tools mid-session. For a practice where stump-infection coding comes up every week, that saves the coder a lookup on every claim.

Catch coding errors before the payer does

Pabau validates ICD-10 codes through the Claim.MD clearinghouse before submission. Laterality errors on stump-infection claims get flagged while your team can still fix them.

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Conclusion

T87.43 has a narrow assignment window. The chart has to document infection, and it has to name the right side, before the code holds.

The denial worth preventing is the one caused by a provider writing “stump infection” with no side named. Fixing that in the note takes seconds. Fixing it in an appeal takes weeks.

Pabau’s claims workflow and Claim.MD validation help wound care and vascular practices catch these errors before submission. Book a demo to see how a T87.43 claim gets checked before it reaches the payer.

Continue your research

Need a clean-claim checklist for post-procedural codes? Clean claim guide covers the documentation and coding requirements that prevent rejections before submission.

Unsure how payer eligibility affects stump-infection claims? Insurance eligibility verification explains how real-time eligibility checks reduce avoidable claim rejections.

Want to understand how denials get resolved after submission? Denial codes in medical billing maps common CARC denial codes to actionable appeals steps.

Frequently asked questions