Use additional code
Does the "use additional code" instruction mean to code the additional code anywhere below the code with that instruction, or does it mean code the additional code immediately after code with the instruction? For example, for a patient with HTN, heart failure, kidney disease, COPD and atrial fib who is admitted to home care with focus of care on hypertension, COPD and atrial fib, would one code I13.0, I50.9, N18.9, J44.9, and then I48.91, or would you code I13.0, J44.9, I48.91, and then code the I50.9 and N18.9? I've had different opinions on this question. Thanks.
I interpret the following to mean "use additional code" goes directly after the code with instruction.
Coding guideline I.A.13. There are manifestation codes that do not have “in diseases classified elsewhere” in the title. For such codes, there is a “use additional code” note at the etiology code and a “code first” note at the manifestation code, and the rules for sequencing apply.
“Code first” and “Use additional code” notes are also used as sequencing rules in the classification for certain codes that are not part of an etiology/ manifestation combination.
Section I.B.7. The sequencing rule is the same as the etiology/manifestation pair, “use additional code” indicates that a secondary code should be added, if known.