A54.40
BillableGonococcal infection of musculoskeletal system, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is A54.40 an HCC code?
Yes. A54.40 maps to Bone/Joint/Muscle Infections/Necrosis under the CMS-HCC V28 risk adjustment model (and Bone/Joint/Muscle Infections/Necrosis 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 A54.40
For A54.40 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 A54.40 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
A54.40 is the ICD-10-CM diagnosis code for gonococcal infection of musculoskeletal system, unspecified. This code describes a bacterial infection caused by gonorrhea that affects the muscles, bones, joints, or connective tissues, but the specific location is not documented. Gonorrhea is a sexually transmitted infection that can spread beyond the genital area to cause inflammation and infection in the musculoskeletal system. A54.40 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering infections with a predominantly sexual mode of transmission (a50-a64).
Under the CMS-HCC V28 risk adjustment model, A54.40 maps to Bone/Joint/Muscle Infections/Necrosis (HCC 92) with a community, non-dual, aged base RAF weight of 0.209. Under the older V24 model, A54.40 mapped to the same category but with a base RAF weight of 0.482 — 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.
If the specific site of musculoskeletal involvement is documented (such as knee, shoulder, or spine), use a more specific code from the A54.4- subcategory rather than the unspecified code. Because A54.40 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 A54.40 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •If the specific site of musculoskeletal involvement is documented (such as knee, shoulder, or spine), use a more specific code from the A54.4- subcategory rather than the unspecified code
- •Verify documentation confirms gonococcal etiology and musculoskeletal involvement; query the provider if the infection site or organism is unclear
Clinical Significance
Gonococcal infection of the musculoskeletal system represents disseminated gonococcal infection, a serious systemic complication of untreated gonorrhea requiring aggressive antibiotic therapy. This unspecified code should prompt a query for more specific site documentation to ensure accurate coding and appropriate risk capture.
Documentation Requirements
- ✓Confirmation of Neisseria gonorrhoeae as the causative organism (culture or NAAT testing)
- ✓Musculoskeletal site involvement documented (even if unspecified, note the clinical presentation)
- ✓Evidence of disseminated gonococcal infection (DGI) versus localized infection
- ✓Treatment regimen documented (typically IV ceftriaxone)
- ✓Response to treatment and any complications