Almost, but not quite: A sequela (UK /skwil/, US /skwl/; usually used in the plural, sequelae) is a pathological condition resulting from a disease, injury, therapy, or other trauma. Typically, a sequela is, in medical language, a chronic condition that is a complication of an acute condition that begins during that acute condition.
If an initial encounter was for something like getting stitches for a laceration, a subsequent visit would be for getting those stitches removed. The sequela would be for treating a resulting infection.
Where I work, we've had ICD-10 codes available for use by our clients for the majority of this year, though we just got database updates for changes in them that will be going into effect on the first. It's kind of a muddle right now because of all the foot-dragging in the required start date: the analytics packages have been requiring ICD-10 for a while to attest for MU, so a lot of people are more confused by the repeated postponements. That and they don't want to update until they have to, and still record some stuff in ICD-9.