ICD-9-CM diagnosis code (retired)
383.31 — Mucosal cyst of postmastoidectomy cavity
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 383.31
383.31 is an ICD-9-CM diagnosis code for mucosal cyst of postmastoidectomy cavity. 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, H95.139 (Mucosal cyst of postmastoidectomy cavity, unspecified ear). The match is approximate, so confirm it against the record.
ICD-10-CM equivalents
- H95.139Mucosal cyst of postmastoidectomy cavity, unspecified earapproximate
Common questions about 383.31
What is the ICD-10 code for ICD-9 383.31?
- The GEMs map 383.31 to ICD-10-CM H95.139.
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.