What is the diagnosis code for a patient with an elevated albumin-to-creatinine (alb/creat) ratio indicating impaired renal function?

Diagnosis Code for Albumin-to-Creatinine Ratio of 144 mg/g

An albumin-to-creatinine ratio (ACR) of 144 mg/g indicates moderately increased albuminuria (category A2) and should be coded as chronic kidney disease (CKD) if confirmed on repeat testing after 3 months, using the appropriate ICD-10 code based on the patient's estimated glomerular filtration rate (eGFR) stage. 1

Understanding the ACR Value

• An ACR of 144 mg/g falls within the A2 category (30-299 mg/g), classified as "moderately increased albuminuria" according to KDIGO guidelines 1
• This level indicates kidney damage and is associated with increased risk for cardiovascular events, CKD progression, and mortality 1
• The term "microalbuminuria" is no longer used and should be avoided 1

Confirming the Diagnosis

Before assigning a definitive CKD diagnosis code, you must confirm persistence of the abnormality:

• Repeat the urine ACR measurement to confirm the elevation is persistent (present for ≥3 months) 1
• A single elevated ACR does not confirm CKD—temporary causes such as fever, exercise, urinary tract infection, heart failure, or menstruation can cause transient elevations 2, 3
• Obtain an eGFR using serum creatinine to determine the GFR category (G1-G5) 1

ICD-10 Coding Framework

The specific ICD-10 code depends on both the GFR category and albuminuria category:

• If eGFR ≥90 mL/min/1.73 m² (G1) with ACR 144: N18.1 (CKD stage 1) 1
• If eGFR 60-89 mL/min/1.73 m² (G2) with ACR 144: N18.2 (CKD stage 2) 1
• If eGFR 45-59 mL/min/1.73 m² (G3a) with ACR 144: N18.30 (CKD stage 3a) 1
• If eGFR 30-44 mL/min/1.73 m² (G3b) with ACR 144: N18.31 (CKD stage 3b) 1
• If eGFR 15-29 mL/min/1.73 m² (G4) with ACR 144: N18.4 (CKD stage 4) 1

Additional Diagnostic Workup Required

Once CKD is confirmed, complete the following assessments:

• Blood pressure measurement 1, 4
• Fasting glucose or HbA1c to assess for diabetes 1
• Lipid panel (total cholesterol, LDL, HDL, triglycerides) 2, 3
• Complete metabolic panel including electrolytes, calcium, phosphorus 2
• Complete blood count to assess for anemia 2
• Renal ultrasound if structural abnormalities are suspected 3

Clinical Implications of A2 Category

This level of albuminuria triggers specific management interventions:

• Initiate or maximize ACE inhibitor or ARB therapy if the patient has hypertension or diabetes 1, 4, 5
• Target blood pressure <140/90 mmHg (or lower if tolerated) 4
• Initiate statin therapy for cardiovascular risk reduction 1
• For patients with type 2 diabetes, strongly consider adding an SGLT2 inhibitor if eGFR ≥20 mL/min/1.73 m² 1, 4
• Monitor ACR and eGFR at least annually, or more frequently based on risk stratification 1

Risk Stratification

An ACR of 144 mg/g places the patient at increased risk:

• The risk for CKD progression, cardiovascular events, and mortality increases continuously above ACR 30 mg/g 1
• Combined with eGFR, this determines monitoring frequency (typically 1-2 times per year for moderate risk) 1
• Patients with diabetes and ACR in the A2 range have significantly elevated risk for progression to end-stage renal disease 1, 5

Common Pitfalls to Avoid

• Do not diagnose CKD based on a single ACR measurement—always confirm persistence over 3 months 1
• Do not use urine dipstick alone—it lacks sensitivity for detecting moderately increased albuminuria 1
• Do not delay treatment while waiting for confirmation—if the patient has diabetes or hypertension with elevated ACR, initiate renin-angiotensin system blockade promptly 1, 4
• Do not forget to assess for reversible causes of albuminuria before confirming CKD 2, 3