Excludes1 pair
A34 vs A35
A34 and A35 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on A35
obstetrical tetanus (A34)
A34
Obstetrical tetanus
Billable
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- A30-A49
Indexed under
- Puerperal, puerperium › tetanus
- Tetanus, tetanic › obstetrical
- Tetanus, tetanic › puerperal, postpartum, childbirth
- Tetanus, tetanic › with › abortion
A35
Other tetanus
Billable
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- A30-A49
Use when the record says
- Tetanus NOS
Indexed under
- Tetanus, tetanic (cephalic) (convulsions)
- Radiculomyelitis › toxic, due to › Clostridium tetani
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027