E89.2 vs R29.0
E89.2 and R29.0 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on R29.0
post-thyroidectomy tetany (E89.2)
E89.2
Postprocedural hypoparathyroidism
Billable
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E89
Use when the record says
- Parathyroprival tetany
Indexed under
- Absence › parathyroid gland (of) (organ or part) (complete or partial)
- Hypoparathyroidism › postprocedural
- Tetany › parathyroprival (due to)
- Tetany › post-thyroidectomy (due to)
- Tetany › postoperative (due to)
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 (due to)
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