- Am I required to install a Concrete-Encased Electrode if one isn't already present?
If there is not one present, you are free to add one if you'd like, two methods are offered in 250.52(A)(3).
The change in the 2005 text was to make it more evident to installers that covering a CEE in concrete does not alleviate our need to connect to it for our grounding electrode system. The CEE (or "Ufer" as it's commonly called) is a very effective grounding electrode for an almost negligible additional cost in most cases, and proposals were submitted to force everyone into noticing. The 2020 as well as other earlier versions of the nec now requires all electrodes available to be used. This means that in new construction a concrete encased electrode must be part of the grounding electrode system. The only exception is for existing buildings. The nec does not require you to chop up the footing to get to an electrode in an existing structure.
Be sure to check local codes before concrete is poured. There has been cases where the inspector made the electrician chop thru the footing to connect to the concrete encased electrode. In NC there is an amendment to forego the requirement to connect to a concrete encased electrode.
Grounding Electrode System - Concrete encased electrode as a sole electrode