ICD-10-CM > S00-T88 > T36-T50 > T45 > T45.A > T45.AX > T45.AX6 T45.AX6 Underdosing of immune checkpoint inhibitors and immunostimulant drugs Non-Billable/Non-Specific Codes T45.AX6A..., initial encounterT45.AX6D..., subsequent encounterT45.AX6S..., sequela