Selected Kidney Function Tests — CPB 0775 | AETNA Coverage Update

Aetna modified CPB 0775 covering selected kidney function tests, effective February 14, 2026, designating eight CPT codes as non-covered for all listed indications. Here's what changes for billing teams.

Aetna, a CVS Health company, updated its kidney function test coverage policy under CPB 0775 to formally classify tests including KidneyIntelX, GFR-NMR, APOL1 genotyping, and transdermal GFR measurement as experimental, investigational, or unproven. The affected codes — 0105U, 0259U, 0355U, 0384U, 0385U, 0407U, 0602T, and 0603T — are now explicitly not covered for any of the indications listed in CPB 0775. If your practice or lab bills these codes for Aetna members, expect denials starting February 14, 2026.

Quick-Reference Table

Aetna Kidney Function Test Coverage Criteria and Medical Necessity Requirements 2026

CPB 0775 is Aetna's clinical policy bulletin governing coverage for selected kidney function tests. This policy has been in place for some time, but the February 14, 2026 modification sharpens the exclusion list considerably — naming specific proprietary tests and CPT codes that will not meet medical necessity under any circumstances listed in the bulletin.

The coverage policy does not create a pathway to coverage for the listed tests. Aetna's position is that the clinical evidence is insufficient to establish effectiveness for these tests. The policy designates these tests as experimental/investigational; consult your Aetna provider agreement for appeals and prior authorization processes.

That's a firm stance. The tests in question include some with significant market presence — KidneyIntelX and IntelxDKD from RenalytixAI have been actively promoted to nephrologists managing diabetic CKD patients. Aetna kidney function test billing for these products now hits a hard wall.

The medical necessity standard Aetna applies here is straightforward: if clinical evidence of effectiveness hasn't been established to Aetna's satisfaction, the test doesn't meet medical necessity. For all eight CPT codes listed in CPB 0775, Aetna has made that determination explicitly. This coverage policy applies across the full range of relevant ICD-10 diagnoses — diabetes mellitus (E08.00–E13.9), CKD stages N18.1–N18.9, hypertensive disease (I10–I16.2), and associated symptom codes.

Aetna Kidney Function Test Exclusions and Non-Covered Indications

This is the core of the CPB 0775 update. Every test listed below is now designated as experimental, investigational, or unproven by Aetna. That designation means no coverage, regardless of diagnosis or clinical justification.

APOL1 renal risk variant genotyping (CPT 0355U) — collected from blood or buccal mucosa. This test identifies genetic variants associated with kidney disease risk. Aetna does not cover it.

GFR-NMR test (CPT 0259U) — uses nuclear magnetic resonance spectroscopy to measure a combination of metabolites including myo-inositol, dimethyl sulfone, valine, and creatinine to assess glomerular filtration rate. Not covered.

KidneyIntelX and IntelxDKD (RenalytixAI) — biomarker panels for predicting renal decline in type 2 diabetes. Both are listed as experimental/investigational in CPB 0775. CPT 0407U is listed as non-covered under the same bulletin for nephrology diabetic CKD indications. Not covered.

NaviDKD and PromarkerD — both are tests for predicting kidney disease in patients with diabetes. These don't yet have unique CPT codes in this bulletin but fall under the broader experimental designation.

RenalVysion (Nephrocor) — used for diagnosing and monitoring kidney disease. Not covered.

Transdermal GFR measurement (CPT 0602T and 0603T) — uses a pyrazine-based fluorescent agent applied transdermally to measure glomerular filtration rate. Both measurement and monitoring codes are excluded.

The real issue here is the commercial landscape. Several of these tests have been actively marketed to clinicians as clinically validated tools. Aetna is saying the published evidence doesn't yet meet its bar. That gap between manufacturer claims and payer coverage is exactly what makes this policy consequential for billing teams.

Coverage Indications at a Glance

Aetna Kidney Function Test Billing Guidelines and Action Items 2026

CPT, HCPCS, and ICD-10 Codes for Selected Kidney Function Tests Under CPB 0775

Not Covered / Experimental CPT Codes

All eight CPT codes listed in CPB 0775 are designated as not covered for the indications in the bulletin. There are no covered CPT codes in this policy update.

Key ICD-10-CM Diagnosis Codes

These diagnosis codes appear in CPB 0775 in the context of the non-covered indications. Pairing any of these with the CPT codes above will not produce a covered claim under Aetna's policy.