Map which Chapter 8 bases apply, then show the need is daily and can be met only in a SNF (the practical-matter test). This is what a coverage reviewer looks for on a Part A day.
Observation & assessment of an unstable condition
A resident on insulin, in recovery from a glycemic crisis, or on a new titrating regimen carries a reasonable potential for hypo/hyperglycemia; interpreting the glucose trend and applying the correction with judgment is skilled and needed daily.
Covered skilled procedure; teaching
Insulin administration and IV medication are covered services under Chapter 8; teaching a complex insulin regimen to competence is a covered skilled service.