2007 ICD-9-CM Procedure 89.18 Other sleep disorder function tests 89.18 is a specific code that can be used to specify a procedure 89.18 contains 3 index entries View the full Volume 3 89.* hierarchy 89.18 also known as: Multiple sleep latency test [MSLT] Index entries containing 89.18: Monitoring sleep (recording) -- see categories 89.17-89.18 Multiple sleep latency test (MSLT) 89.18 Test, testing (for) sleep disorder function -- see categories 89.17-89.18