ICD-10-CM > S00-T88 > T36-T50 > T47 > T47.0 > T47.0X > T47.0X6 T47.0X6 Underdosing of histamine H2-receptor blockers Non-Billable/Non-Specific Codes T47.0X6A..., initial encounterT47.0X6D..., subsequent encounterT47.0X6S..., sequela