Sequencing relationship
What we found
Sequence I97.190 before I21.A9
I21.A9 carries a Code First instruction covering I97.190: “, if applicable, postprocedural myocardial infarction following cardiac surgery (I97.190), or postprocedural myocardial infarction during cardiac surgery (I97.790)”
What to review
On a claim that carries both, list I97.190 ahead of I21.A9; the manifestation is never the principal diagnosis.
Why it matters
A "Code first" note means the underlying etiology is sequenced ahead of this manifestation code on the claim.
Source / rule
CMS ICD-10-CM tabular instructional notes