ICD-10-CM > K00-K95 > K65-K68 > K68 K68 Disorders of retroperitoneum Non-Billable/Non-Specific Codes K68.1Retroperitoneal abscessK68.11Postprocedural retroperitoneal abscessK68.12Psoas muscle abscessK68.19Other retroperitoneal abscessK68.2Retroperitoneal fibrosisK68.3Retroperitoneal hematomaK68.9Other disorders of retroperitoneum