T87.1X9
BillableComplications of reattached (part of) unspecified lower extremity
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is T87.1X9 an HCC code?
Yes. T87.1X9 maps to Traumatic Amputations and Complications under the CMS-HCC V28 risk adjustment model (and Traumatic Amputations and Complications under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.
MEAT Criteria for T87.1X9
For T87.1X9 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 T87.1X9 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
T87.1X9 is the ICD-10-CM diagnosis code for complications of reattached (part of) unspecified lower extremity. Problems or complications that occur after a leg or foot (or part of it) has been surgically reattached, when it is unclear which side (left or right) is affected. T87.1X9 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, T87.1X9 maps to Traumatic Amputations and Complications (HCC 405) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, T87.1X9 mapped to the same category but with a base RAF weight of 0.350 — 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 laterality (left vs. right) cannot be determined from documentation. Because T87.1X9 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 T87.1X9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Complications of reattached unspecified lower extremity represent documented problems with lower limb reattachment where laterality is not specified. These complications still carry significant implications for mobility and function requiring specialized care.
Documentation Requirements
- ✓Documentation of lower extremity reattachment procedure
- ✓Evidence of complications related to reattachment
- ✓Rationale for unspecified laterality designation
- ✓Clinical findings supporting complication diagnosis
- ✓Functional status and mobility assessment
- ✓Treatment plans addressing complications
- ✓Provider assessment confirming reattachment etiology
- ✓Plans for laterality clarification if feasible
Commonly Confused Codes
- •T87.1X1 — complications of reattached right lower extremity (unspecified vs right)
- •T87.1X2 — complications of reattached left lower extremity (unspecified vs left)
- •Z89.619 — acquired absence of unspecified leg (complication vs status)
- •T87.30 — neuroma of amputation stump, unspecified extremity (reattachment vs amputation)
- •T87.2 — complications of other reattached body part (lower extremity vs other)