What is ICD-10 code T87.40?

T87.40 is the ICD-10-CM diagnosis code for Infection of amputation stump, unspecified extremity. A bacterial or fungal infection occurring at an amputation site when the specific limb location is not documented or specified. T87.40 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. T87.40 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. T87.40 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. T87.40 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does T87.40 map to under V28?

T87.40 maps to CMS-HCC V28 409 (Amputation Status, Lower Limb/Amputation Complications). The category number and label come from the CMS-HCC V28 model file for payment year 2026.

What does T87.40 pay in RAF?

T87.40 carries a community, non-dual, aged (CNA) RAF weight of 0.598 under CMS-HCC V28 for payment year 2026. The weight comes from the CMS V28 relative-factor file, not a hand-typed table.

What is the V28 vs V24 difference for T87.40?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For T87.40, V28 maps to Amputation Status, Lower Limb/Amputation Complications at RAF 0.598 while V24 mapped to Amputation Status, Lower Limb/Amputation Complications at RAF 0.519. Both models can still appear in legacy data and in payer-specific lookback periods.

What documentation supports T87.40?

Use this code only when the specific extremity cannot be determined; otherwise use more specific codes T87.41-T87.44 Document the causative organism and severity of infection for complete clinical picture Because T87.40 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score. See the MEAT criteria checklist at /meat-criteria for what Monitor, Evaluate, Assess, or Treat looks like in a note. MEAT is generic documentation evidence, not a payer-specific rule.

2026 ICD-10-CM T87.40: Infection of amputation

T87.40 maps to CMS-HCC V28 409 (RAF 0.598). Documentation must support MEAT. MEAT criteria · RAF calculator · free HCC coding tools

ICD-10-CM Code View

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Code lookupT87.40Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Injury, poisoning and certain other consequences of external causes (S00-T88) / Complications of surgical and medical care, not elsewhere classified (T80-T88)

T87.40

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Infection of amputation stump, unspecified extremity

A bacterial or fungal infection occurring at an amputation site when the specific limb location is not documented or specified.

Buddy Insight

Infection of amputation stump represents a serious post-surgical complication requiring immediate antibiotic therapy and potential surgical intervention.

CMS-HCC V28

Mapped

HCC 409

Amputation Status, Lower Limb...

RAF 0.598

CMS-HCC V24

Mapped

HCC 189

Amputation Status, Lower Limb...

RAF 0.519

ACA/HHS

Mapped

HCC 234

HHS-HCC 234

Varies by metal level

ESRD/PACE

Mapped

HCC 189

Amputation Status, Lower Limb...

RAF 0.081

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

T87Complications peculiar to reattachment and amputation

T87.4Infection of amputation stump

T87.40Infection of amputation stump, unspecified extremity

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for T87.40 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for T87.40 in this effective period.

Related Child Codes

Official

T87.41Infection of amputation stump, right upper extremity

T87.42Infection of amputation stump, left upper extremity

T87.43Infection of amputation stump, right lower extremity

T87.44Infection of amputation stump, left lower extremity

Includes

Official

ICD-10-CM does not list Includes notes for T87.40 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for T87.40 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for T87.40 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for T87.40 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for T87.40 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of infection at amputation stump site

Clinical signs of infection (erythema, warmth, purulent drainage)

Laboratory evidence supporting infection (elevated WBC, cultures)

Specific organism identification when available

MEAT Support

HCC Buddy guidance

Documentation of infection at amputation stump site

Clinical signs of infection (erythema, warmth, purulent drainage)

Laboratory evidence supporting infection (elevated WBC, cultures)

Specific organism identification when available

Audit Caution

HCC Buddy guidance

Using this unspecified code when specific extremity location is documented

Failing to code the specific infectious organism when identified

Missing associated diabetes or other risk factors that may affect treatment

Not coding additional manifestations of systemic infection if present

Common Mistakes

HCC Buddy guidance

T87.41-T87.44 — Site-specific infection codes when extremity is documented

L03.9 — Cellulitis unspecified vs specific amputation stump infection

T81.4 — Infection following procedure, not elsewhere classified

Z87.891 — Personal history of nicotine dependence (may be risk factor)

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is T87.40 an HCC code?

Yes. T87.40 (Infection of amputation stump, unspecified extremity) maps to Amputation Status, Lower Limb/Amputation Complications under the CMS-HCC V28 risk adjustment model (and Amputation Status, Lower Limb/Amputation Complications under V24), with a community non-dual aged RAF of 0.598. It is billable for payment year 2026.

Coder answer: T87.40 is billable and maps to V28 HCC 409, Amputation Status, Lower Limb/Amputation Complications. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: T87.40
Description: Infection of amputation stump, unspecified extremity
HCC (V28): HCC 409 — Amputation Status, Lower Limb/Amputation Complications
RAF: 0.598
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 409, Amputation Status, Lower Limb/Amputation Complications

0.598

V24HCC 189, Amputation Status, Lower Limb/Amputation Complications

0.519

ESRDHCC 189, Amputation Status, Lower Limb/Amputation Complications

0.081

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work T87.40 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for T87.40

For T87.40 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed T87.40 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

T87.40 is the ICD-10-CM diagnosis code for infection of amputation stump, unspecified extremity. A bacterial or fungal infection occurring at an amputation site when the specific limb location is not documented or specified. T87.40 sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering complications of surgical and medical care, not elsewhere classified (t80-t88).

Under the CMS-HCC V28 risk adjustment model, T87.40 maps to Amputation Status, Lower Limb/Amputation Complications (HCC 409) with a community, non-dual, aged base RAF weight of 0.598. Under the older V24 model, T87.40 mapped to the same category but with a base RAF weight of 0.519, V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Use this code only when the specific extremity cannot be determined; otherwise use more specific codes T87.41-T87.44. Because T87.40 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for T87.40 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code only when the specific extremity cannot be determined; otherwise use more specific codes T87.41-T87.44
•Document the causative organism and severity of infection for complete clinical picture

Clinical Significance

Infection of amputation stump represents a serious post-surgical complication requiring immediate antibiotic therapy and potential surgical intervention. This diagnosis indicates poor wound healing and increased risk of sepsis or need for revision amputation.