ICD-10-CM > S00-T88 > T36-T50 > T45 > T45.4 > T45.4X > T45.4X6 T45.4X6 Underdosing of iron and its compounds Non-Billable/Non-Specific Type 1 Excludes iron deficiency (E61.1) Codes T45.4X6A..., initial encounterT45.4X6D..., subsequent encounterT45.4X6S..., sequela