Excludes1 pair

F44.5 vs R29.0

F44.5 and R29.0 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 R29.0
hysterical tetany (F44.5)
F44.5

Conversion disorder with seizures or convulsions

Billable
Chapter 5
Mental, Behavioral and Neurodevelopmental disorders
Section
F40-F48
Use when the record says
  • Conversion disorder with attacks or seizures
  • Dissociative convulsions
Indexed under
  • Hysteroepilepsy
  • Autonomic, autonomous › hysteria seizure
  • Convulsions › dissociative
  • Convulsions › hysterical
  • Fit › hysterical
R29.0

Tetany

Billable
Chapter 18
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Section
R25-R29
Use when the record says
  • Carpopedal spasm
Indexed under
  • Pseudotetany
  • Tetany (due to)
  • Diathesis › spasmophilic
  • Syndrome › magnesium-deficiency
  • Tetany › convulsions

These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.

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