Underdosing of antithyroid drugs, sequela

This code indicates a long-term consequence or complication arising from the patient not receiving enough antithyroid medication. This underdosing led to a persistent health problem that is now being addressed. The original underdosing event is no longer an active problem, but its lasting effects are.

Assign this code when a patient presents with a chronic condition or permanent damage directly attributable to a past period of insufficient antithyroid drug administration. This is appropriate for conditions like persistent hyperthyroidism or related complications that developed due to the underdosing and are now being managed. Do not use this code for acute or active underdosing.

• Requires an additional code to specify the nature of the sequela (e.g., specific endocrine disorder).
• Only use for conditions that are residual effects, not for the active underdosing event itself.
• Documentation must clearly link the current condition to a past underdosing of antithyroid medication.