Your vendor is wrong, as they often are, they are there to make a sale, I make it a rule to always do my own research. L4360 and L4361 are both pneumatic. They usually have a small pouch in front filled with air that you press to fill the boot with air and thus make it fit snugger to the patient. The 2 codes are for the same product, a prefabricated walking boot. The difference is that the L4360 code indicates the doctor had to make some adjustments to the boot to make it fit (this does not happen often and in my opinion this code will not be the code you use regularly). Any adjustment to "customize" the boot must be documented clearly, a templated comment that mimics the code definition is not sufficient. It must be specific to the patient and why the customization was made. By the way, the 2 codes reimburse the same, so why make things difficult by billing the L4360. Here are the code definitions:
L4360 Walking boot, pneumatic and/or vacuum, with or without joints, with or without interface material, prefabricated item that has been trimmed, bent, molded, assembled, or otherwise customized to fit a specific patient by an individual with expertise
Possible Examples: Pneumatic-type
L4361 Walking boot, pneumatic and/or vacuum, with or without joints, with or without interface material, prefabricated, off-the-shelf
L4386 Walking boot, non-pneumatic, with or without joints, with or without interface material, prefabricated item that has been trimmed, bent, molded, assembled, or otherwise customized to fit a specific patient by an individual with expertise
Allowable: $128.12 - $170.83
Possible Examples: CAM-Walker
L4387 Walking boot, non-pneumatic, with or without joints, with or without interface material, prefabricated, off-the-shelf