K04.4 vs K05
K04.4 and K05 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 K04.4
acute periodontitis (K05.2-)
K04.4
Acute apical periodontitis of pulpal origin
Billable
- Chapter 11
- Diseases of the digestive system
- Section
- K00-K14
Use when the record says
- Acute apical periodontitis NOS
Indexed under
- Septic › teeth, tooth
- Periodontitis › apical › acute (chronic) (complex) (compound) (local) (simplex)
K05
Gingivitis and periodontal diseases
Not billable
- Chapter 11
- Diseases of the digestive system
- Section
- K00-K14
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