ICD-9-CM diagnosis code (retired)
522.6 — Chronic apical periodontitis
ICD-9-CM was replaced by ICD-10 on October 1, 2015. These are the ICD-10-CM equivalents from the CMS General Equivalence Mappings.
About ICD-9-CM 522.6
522.6 is an ICD-9-CM diagnosis code for chronic apical periodontitis. ICD-9-CM was retired for U.S. claims on October 1, 2015, when ICD-10-CM took over.
The CMS General Equivalence Mappings translate it to one ICD-10-CM code, K04.5 (Chronic apical periodontitis). The match is exact.
ICD-10-CM equivalents
- K04.5Chronic apical periodontitisexact match
Common questions about 522.6
What is the ICD-10 code for ICD-9 522.6?
- The GEMs map 522.6 to ICD-10-CM K04.5.
GEMs are a translation aid, not a substitute for coding from the record. The 2027 ICD-10 code set has changed since the last GEMs release in 2018. Page updated September 29, 2026.