A long-time classification divided the family into Nakh and Dagestanian branches, whence the term Nakho-Dagestanian.
However, attempts at reconstructing the protolanguage suggest that the Nakh languages are no more divergent from Dagestanian than the various branches of Dagestanian are from each other, although this is still not universally accepted.
The following outline, based on the work of linguist Bernard Comrie and others, has been adopted by Ethnologue.
An Avar–Andi–Dido branch was abandoned, but has been resurrected as the "New Type" languages in Schulze (2009, 2013), and Lak–Dargwa has likewise returned.

One factor complicating internal classification within the family is that the diachronic development of its respective branches is marked both by an extreme degree of diffusion and divergence followed by secondary convergence, which complicates the comparative method.

Population data is from Ethnologue 16th ed.
A long-time classification divided the family into Nakh and Dagestanian branches, whence the term Nakho-Dagestanian. However, attempts at reconstructing the protolanguage suggest that the Nakh languages are no more divergent from Dagestanian than the various branches of Dagestanian are from each other, although this is still not universally accepted. The following outline, based on the work of linguist Bernard Comrie and others, has been adopted by Ethnologue. An Avar–Andi–Dido branch was abandoned, but has been resurrected as the "New Type" languages in Schulze (2009, 2013), and Lak–Dargwa has likewise returned.
One factor complicating internal classification within the family is that the diachronic development of its respective branches is marked both by an extreme degree of diffusion and divergence followed by secondary convergence, which complicates the comparative method.
Population data is from Ethnologue 16th ed.
Northeast Caucasian languages