How would you code this and how would you find the parts in the Alpha Index of ICD10:

Direct infection of the left ankle due to leprosy (Mycobacterium leprae).

The correct answer is A30.9, M01.X72.

My students correctly found the Mycobacterium Leprae Leprosy A30.9 with little issue.

They could not find the M01.X72 which is Direct infection of left ankle and foot infectious and parasitic diseases classified elsewhere.

Where is this second in the Alpha Index? How would they have even know it’s a "disease classified elswhere" code.

I have searched and searched and I find no tangible answers.

Please help…..