You ask a great question without a simple answer. There are no guidelines that really address your question adequately since CKD staging is not a precise way to classify patients. The current staging system (1 through 5) ignores proteinuria, an extremely important variable. A patient CKD 3 who has no proteinuria is much less likely to progress than a a patient with stage 2 CKD who has heavy proteinuria. Therefore, it is difficult to make recommendations for followup, based solely on stage.
Having said this, here are some general guideline:
Patients with stable CKD 1-3 without proteinuria and well controlled blood pressure might be seen every 9-12 months by a nephrologist. It might be reasonable for such patients to see their family doctors more frequently for blood pressure checks. Some patients with the above features and CKD stage 1-2 might not even require nephrology input at all.
Patients with stable CKD 1-3 who have significant proteinuria (greater than 1 g / day) might be seen more frequently (every 3-6 months) by their nephrologist in order to adjust medications intended to reduce protein excretion.
Patients with CKD 4-5 might need more frequent monitoring by their nephrologist (every 1-3 months) particularly if phosphate binders or erythropoeitin are being used. Such patients might be best managed in a multidisciplinary renal management clinic.
Remember, these are only general guidelines and some patient s may not suit the recommendations above.