N18.5

Chronic kidney disease, stage 5

Chronic kidney disease, stage 5 (CKD stage 5) is a severe clinical state characterized by a glomerular filtration rate (GFR) of less than 15 mL/min/1.73 m². At this advanced stage, the kidneys have lost nearly all functional capacity to filter metabolic waste products, maintain electrolyte balance, and regulate fluid volume. This stage is often referred to as pre-end-stage renal disease, as the patient is either approaching or has reached the point where life-sustaining renal replacement therapy (RRT), such as hemodialysis, peritoneal dialysis, or kidney transplantation, is necessary for survival. The physiological impact is systemic, frequently resulting in uremia, metabolic acidosis, hyperkalemia, and secondary hyperparathyroidism. Clinical management focuses on symptom control, preparation for dialysis or transplant, and mitigating the high risk of cardiovascular complications associated with profound renal impairment.

Clinical Symptoms

Severe fatigue and generalized weakness
Persistent nausea and vomiting
Loss of appetite and metallic taste in the mouth
Generalized pruritus (itching) often worse at night
Significant peripheral edema (swelling of legs, ankles, or feet)
Shortness of breath (dyspnea) due to pulmonary congestion or anemia
Decreased urine output (oliguria) or inability to urinate (anuria)
Uremic encephalopathy causing confusion or difficulty concentrating
Muscle twitching, cramps, or restless leg syndrome
Uremic frost (fine white powder of urea crystals on the skin)
Resistant hypertension
Insomnia and other sleep disturbances
Chest pain related to uremic pericarditis

Common Causes

Diabetic nephropathy (Type 1 or Type 2 diabetes mellitus)
Hypertensive nephrosclerosis
Chronic glomerulonephritis
Autosomal dominant polycystic kidney disease (ADPKD)
Systemic lupus erythematosus (SLE) nephritis
Obstructive uropathy (e.g., chronic prostatic hyperplasia or bilateral nephrolithiasis)
Vesicoureteral reflux
Alport syndrome
Chronic pyelonephritis
Analgesic nephropathy and other drug-induced chronic interstitial nephritis

Documentation & Coding Tips

Explicitly state the estimated Glomerular Filtration Rate (eGFR) and the duration of the condition.

Example: Patient presents with chronic kidney disease stage 5 as evidenced by a stable eGFR of 12 mL/min/1.73 m2 over the last 4 months. Current status is pre-dialysis with no immediate plans for renal replacement therapy this week. Risk adjustment: This documentation supports HCC 136 for Chronic Kidney Disease Stage 5.

Billing Focus: Documentation must specify the stage (Stage 5) to justify the ICD-10-CM code N18.5 rather than a non-specific CKD code.

Distinguish between Chronic Kidney Disease Stage 5 and End Stage Renal Disease.

Example: Patient has advanced chronic kidney disease stage 5. Although the eGFR is 8 mL/min/1.73 m2, the patient has opted for conservative management and is not currently receiving dialysis, nor is dialysis clinically mandated at this visit. Billing Focus: N18.5 is appropriate here; N18.6 (ESRD) should only be used if the patient is on chronic dialysis.

Billing Focus: Code N18.5 is for patients with eGFR < 15 who are NOT on chronic dialysis.

Document the underlying etiology and all associated complications such as anemia or bone disease.

Example: Assessment: Hypertensive chronic kidney disease, stage 5. Also noted is anemia of chronic kidney disease and secondary hyperparathyroidism. Plan: Continue Lisinopril for BP control, start Epoetin alfa for anemia, and Sevelamer for phosphate control. Billing Focus: Requires I12.0 as the primary code with N18.5 as a secondary code.

Billing Focus: Requires sequencing of underlying causes like diabetes (E11.22) or hypertension (I12.0) before the N18.5 code.

Identify and record uremic signs and symptoms to support medical necessity for frequent monitoring.

Example: Patient reports worsening uremic pruritus and mild morning nausea. Physical exam reveals metallic taste and pericardial friction rub. GFR remains at 11 mL/min/1.73 m2. Diagnosis: Chronic kidney disease stage 5 with uremic symptoms. Risk Adjustment: Uremia indicates a higher severity within the stage 5 classification.

Billing Focus: Documentation of symptoms supports the medical decision-making complexity for higher-level E/M codes.

Document the specific plan for renal replacement therapy or palliative care.

Example: Patient with chronic kidney disease stage 5 is being prepared for hemodialysis. Arteriovenous fistula was created in the left forearm last month. Currently awaiting maturation. Patient stable on medical management for now. Billing Focus: Use Z99.2 if the patient had started dialysis; since they have not, N18.5 remains primary.

Billing Focus: Clarifies the transition point between N18.5 and N18.6.

Relevant CPT Codes

99214 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a moderate level of medical decision making. Documented time: 30-39 minutes.
CKD Stage 5 is a chronic illness with a high risk of morbidity, typically requiring moderate MDM for routine management.
99215 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a high level of medical decision making. Documented time: 40-54 minutes.
Used when Stage 5 CKD is unstable, uremic symptoms are present, or multiple acute complications must be managed concurrently.
90960 - End-stage renal disease related services monthly, for patients 20 years of age and older; with 4 or more face-to-face visits per month
While N18.5 technically precedes ESRD, this code is often applied as patients transition to dialysis management while still coded as Stage 5 in records.
36821 - Arteriovenous anastomosis, direct, any site (e.g., Cimino-type) (separate procedure)
Surgical preparation for hemodialysis is a hallmark of Stage 5 CKD management.
93976 - Duplex scan of abdominal, pelvic, genitourinary system organs and/or visceral artery outflow, limited study
Used to monitor kidney size, cortical thickness, and vascular flow in advanced CKD.
99204 - Office or other outpatient visit for the evaluation and management of a new patient, which requires a moderate level of medical decision making. Documented time: 45-59 minutes.
Standard for a new referral of a Stage 5 CKD patient to a specialist.
99205 - Office or other outpatient visit for the evaluation and management of a new patient, which requires a high level of medical decision making. Documented time: 60-74 minutes.
Required for complex new patients with Stage 5 CKD and multiple systemic failures (heart failure, diabetes).
90935 - Hemodialysis procedure with single evaluation by a physician or other qualified health care professional
For Stage 5 CKD patients who require urgent dialysis during an inpatient stay.
36830 - Creation of arteriovenous fistula by other than direct anastomosis; with graft (e.g., PTFE)
Alternative vascular access for patients whose veins are unsuitable for a direct fistula.
99213 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a low level of medical decision making. Documented time: 20-29 minutes.
Used for stable Stage 5 CKD patients presenting for minor adjustments or specific lab reviews.