N18.31
BillableChronic kidney disease, stage 3a
HCC Category Mapping
V28HCC 329 — Pressure Ulcer of Skin with Necrosis Through to Muscle, Tendon, or Bone
1.071V24HCC 138 — Chronic Kidney Disease, Moderate (Stage 3)
0.000ESRDHCC 138 — Chronic Kidney Disease, Moderate (Stage 3)
0.000What This Code Means
Stage 3a chronic kidney disease where kidney function is moderately decreased with a GFR of 45-59, representing the milder end of stage 3.
Coding Tips
- •Verify GFR range of 45-59 mL/min/1.73m² is documented to distinguish from stage 3b
- •Document the cause of CKD (diabetes, hypertension, glomerulonephritis) with an additional diagnosis code
Clinical Significance
Stage 3a chronic kidney disease represents mild to moderate kidney function decline (GFR 45-59) requiring nephrology consultation and cardiovascular risk management. This diagnosis indicates established CKD requiring ongoing monitoring but typically has minimal direct RAF impact in standard HCC models.
Documentation Requirements
- ✓Chronic kidney disease stage 3a specifically documented
- ✓GFR values in the 45-59 range confirming stage 3a
- ✓Underlying cause of CKD documented if known
- ✓Nephrology consultation or management plan
- ✓Cardiovascular risk stratification and management
- ✓Laboratory monitoring schedule for progression
- ✓Patient education on CKD management documented
Commonly Confused Codes
Code Hierarchy
└N18Chronic kidney disease (CKD)└N18.3Chronic kidney disease, stage 3 (moderate)└N18.31Chronic kidney disease, stage 3a
└N18.31Chronic kidney disease, stage 3a