ICD-9-CM diagnosis code (retired)
327.21 — Primary central sleep apnea
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 327.21
327.21 is an ICD-9-CM diagnosis code for primary central sleep apnea. 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, G47.31 (Primary central sleep apnea). The match is exact.
ICD-10-CM equivalents
- G47.31Primary central sleep apneaexact match
Common questions about 327.21
What is the ICD-10 code for ICD-9 327.21?
- The GEMs map 327.21 to ICD-10-CM G47.31.
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.