Stage 1: Normal GFR (≥ 90 mL / min/1.73 m 2) plus either persistent albuminuria or known structural or hereditary renal disease Stage 2: GFR 60 to 89 mL / min/1.73 m 2 Stage 3a: 45 to 59 mL / min/1.73 m 2 Stage 3b: 30 to 44 mL / min/1.73 m 2 Stage 4: GFR 15 to 29 mL / min/1.73 m 2 Stage 5: GFR < 15 mL / min/1.73 m 2 GFR (in mL / min/1.73 m 2) in CKD can be estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI 2021) creatinine equation: In contrast to prior versions, the most recent equation does not adjust for race, so as to reduce racial inequities in CKD diagnosis and thus, treatment.