Final answer:
In the ICD-10-CM, NEC stands for 'Not elsewhere classifiable', indicating a situation where a specific condition does not have a precise code within the coding system.
Step-by-step explanation:
In the ICD-10-CM tabular list of abbreviations, NEC stands for 'Not elsewhere classifiable'. This abbreviation is used when a specific condition cannot be found in the ICD-10-CM under a more precise code. It is not 'necrotizing enterocolitis', which is a specific disease coded elsewhere, nor 'Non-eligible Code' or 'Normal encounter coding', which are not standard ICD-10-CM terminology.