Sequencing relationship
What we found
Sequence A41.9 before R65.2
R65.2 carries a Code First instruction covering A41.9: “sepsis NOS (A41.9)”
What to review
On a claim that carries both, list A41.9 ahead of R65.2; 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