My understanding of the 2023 ICD-10 guidelines is that the primary diagnosis of obesity/overweight has to be documented by your provider. However, the secondary diagnosis of BMI can be taken from another provider's documentation and doesn't necessarily have to be documented by your provider. See below for the exact wording of the ICD-10 guidelines. Hope this helps!
ICD-10-CM Guidelines FY 2023 Pages 15-16
Documentation by Clinicians Other than the Patient's Provider
Code assignment is based on the documentation by the patient's provider (i.e., physician or other qualified healthcare practitioner legally accountable for establishing the patient's diagnosis). There are a few exceptions when code assignment may be based on medical record documentation from clinicians who are not the patient’s provider (i.e., physician or other qualified healthcare practitioner legally accountable for establishing the patient’s diagnosis). In this context, “clinicians” other than the patient’s provider refer to healthcare professionals permitted, based on regulatory or accreditation requirements or internal hospital policies, to document in a patient’s official medical record.
These exceptions include codes for:
• Body Mass Index (BMI)
• Depth of non-pressure chronic ulcers
• Pressure ulcer stage
• Coma scale
• NIH stroke scale (NIHSS)
• Social determinants of health (SDOH)
• Laterality
• Blood alcohol level
• Underimmunization status
This information is typically, or may be, documented by other clinicians involved in the care of the patient (e.g., a dietitian often documents the BMI, a nurse often documents the pressure ulcer stages, and an emergency medical technician often documents the coma scale). However, the associated diagnosis (such as overweight, obesity, acute stroke, pressure ulcer, or a condition classifiable to category F10, Alcohol related disorders) must be documented by the patient’s provider. If there is conflicting medical record documentation, either from the same clinician or different clinicians, the patient’s attending provider should be queried for clarification.
The BMI, coma scale, NIHSS, blood alcohol level codes, codes for social determinants of health and underimmunization status should only be reported as secondary diagnoses.