Objective: Persons with diabetes but no chronic kidney disease (CKD) and without albuminuria have the same age-related decline in kidney function as the background population. Whether this also applies following moderate loss in kidney function is unknown. We quantified the impact of albuminuria status on the development of estimated glomerular filtration rate (eGFR) trajectories following CKD stage 3 (CKD3) and assessed potential heterogeneous development patterns among the subgroup with normoalbuminuria. Research Design and Methods: We used repeated clinical measures during up to 16 years of follow-up in 935 persons with type 1 diabetes and 1,984 with type 2 diabetes. Trajectories of eGFR by diabetes type and albuminuria status following CKD3 were estimated with spline mixed-effects models with adjustment for relevant confounders. Latent class trajectory modeling was used to find distinct patterns of eGFR development in the subgroups with normoalbuminuria. Results: Mean annual declines in eGFR for normo-, micro- and macroalbuminuria the first 10 years following CKD3 were 1.9, 2.3, and 3.3 mL/min/1.73 m² in type 1 diabetes and 1.9, 2.1, and 3.0 in type 2 diabetes, respectively. For normoalbuminuria, two distinct eGFR patterns were found, one with accelerated declining eGFR levels. This specific progression pattern was associated with less use of lipid-lowering treatment, renin-angiotensin system blockers, and other antihypertensive treatment. Conclusions: Our results support a diabetes-dependent decline in kidney function without albuminuria following CKD3, with a subgroup showing a progressive decline. Furthermore, this group seems to be undertreated in terms of cardioprotective and renal protective treatment and suggests that increased attention should be drawn to normoalbuminuric diabetic kidney disease.