Primary Care Coding Alert

Answer: Coding sequela is commonly misunderstood among coders. There are several things to consider when deciding how to code sequela.

First, it’s important to understand what sequela is. ICD-10-CM Official Guidelines, Section I.B.10, says this: “A sequela is the residual effect (condition produced) after the acute phase of an illness or injury has terminated. There is no time limit on when a sequela code can be used. The residual may be apparent early, such as in cerebral infarction, or it may occur months or years later, such as that due to a previous injury.”

This means that once an injury or illness is healed or resolved, any new issues that develop due to the original injury/illness are considered sequela. This can still be confusing, however, because we know that any aftereffect is technically the result of a condition. Just because a complication had a discernible cause does not mean it can be reported as sequela.

Let’s say a patient has a UTI that’s caused by a staph infection. You’d code that using two codes, such as N39.0 (Urinary tract infection, site not specified) and B95.- (Streptococcus, Staphylococcus, and Enterococcus as the cause of diseases classified elsewhere). Even though the UTI is a result of the infection, you would not report that as sequela. The UTI is not a residual effect of the staph infection that appeared after the staph infection was completely resolved. Rather, the staph infection created an environment that welcomed the UTI. It’s that reasoning that also explains why complications from a medical procedure are also not regarded as sequela.

When dealing with injuries, those are instances when the 7th character is necessary. Sequelae that occur as a result of an injury or accident don’t have their own codes, which is why ICD-10 guideline I.C.19a tells you to add the 7th character S to the injury code to identify that the injury was the cause of the sequela. You would want to sequence the type of sequela first, followed by the injury code with the 7th character S tacked onto the end. The same goes for a scar resulting from a burn. If a patient comes in for treatment of a burn scar, the scar would be a sequela of a previous burn. You would code the scar first because that’s what the physician is treating. Then you code the burn injury and add S to the burn injury code to indicate the burn caused the scar.

Note: Some sequelae have their own codes that don’t require the 7th character S. Let’s say a patient suffers a stroke. After the patient’s stroke has resolved, they may experience memory loss or trouble with language, which would be sequela. This would be coded with I69.011 (Memory deficit following nontraumatic subarachnoid hemorrhage) and I69.02- (Speech and language deficits following nontraumatic subarachnoid hemorrhage).