As part of the 2021 changes to CMS69, there is a requirement added for Above/Below Normal BMI interventions to have a reason code:

• "Most Recent Documented BMI" MostRecentBMI
  with ["Intervention, Performed": "Follow Up for Above Normal BMI"] AboveNormalFollowUp
  such that MostRecentBMI.relevantDatetime 12 months or less on or before day of start of AboveNormalFollowUp.relevantPeriod
  and AboveNormalFollowUp.reason in "Overweight or Obese" where MostRecentBMI.result >= 25 'kg/m2'

• "Most Recent Documented BMI" MostRecentBMI
  with ["Intervention, Performed": "Follow Up for Below Normal BMI"] BelowNormalFollowUp
  such that MostRecentBMI.relevantDatetime 12 months or less on or before day of start of BelowNormalFollowUp.relevantPeriod
  and BelowNormalFollowUp.reason ~ "Underweight (finding)" where MostRecentBMI.result < 18.5 'kg/m2'

Clinically speaking, the BMI value itself may serve as a "reason" for the follow up without an diagnosis code being documented, which is the reason for the following 2 questions:

1. Given that a patient may not have any diagnosis of "overweight" or "underweight" in a given visit, is the BMI value sufficient to provide numerator credit if a patient has an above or below normal vitals value for BMI and Intervention is provided?

OR

2. Is it required that code is documented by the provider seeing the patient that the followup provided was explicitly for "Overweight or Obese" or "Underweight (finding)"

And 3. If reason is required, why is it not required for medication orders?