What does the term "sequela" refer to in ICD-10-CM coding?

In ICD-10-CM coding, the term "sequela" refers to the late effects of a condition or injury that occur after the initial problem has resolved. It signifies the lasting consequences that remain following a previous illness or injury, which can impact the patient's health or function. For example, if a patient experiences a stroke and later has residual effects like weakness or speech difficulties, these would be classified as sequelae of the stroke.

The understanding of sequelae is important in coding because it affects how the provider documents the patient's ongoing health issues that are directly linked to prior conditions. This term is distinct from initial and subsequent encounters, which refer to the timing of treatment relative to the patient's ongoing care, and from complications, which suggest new or additional problems that arise during the course of treatment.