Final answer:
A code from Chapter 18 should be assigned if a definitive diagnosis is documented.
Step-by-step explanation:
The statement is false. A code from Chapter 18 should be assigned if a definitive diagnosis is documented. Chapter 18 of the International Classification of Diseases (ICD) system is specific to symptoms, signs, and abnormal clinical and laboratory findings, not definitive diagnoses. It provides codes for conditions such as edema, fever, pain, abnormal blood test results, etc.
For example, if a patient has a fever due to an infection, the appropriate code from Chapter 18 would be assigned to indicate the symptom of the fever. A separate code from a different chapter would be assigned to indicate the definitive diagnosis of the infection.
In conclusion, the assignment of a code from Chapter 18 is necessary when documenting symptoms or abnormal clinical and laboratory findings, regardless of whether a definitive diagnosis is also documented.