ICD-10 Code for Corrosion
Also indexed as (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
The ICD-10-CM code for corrosion is T30.4 — Corrosion of unspecified body region, unspecified degree. This is the code the Alphabetic Index gives for corrosion with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
BillableUnspecified
T30.4 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which corrosion code should you use?
The Alphabetic Index lists 448 codes under Corrosion. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| abdomen, abdominal | T21.42 | Corrosion of unspecified degree of abdominal wall | not billable |
| above elbow | T22.439 | Corrosion of unspecified degree of unspecified upper arm | not billable |
| alimentary tract NEC | T28.7 | Corrosion of other parts of alimentary tract | not billable |
| ankle | T25.419 | Corrosion of unspecified degree of unspecified ankle | not billable |
| axilla | T22.449 | Corrosion of unspecified degree of unspecified axilla | not billable |
| back | T21.44 | Corrosion of unspecified degree of lower back | not billable |
| buttock | T21.45 | Corrosion of unspecified degree of buttock | not billable |
| calf | T24.439 | Corrosion of unspecified degree of unspecified lower leg | not billable |
| cervix | T28.8 | Corrosion of internal genitourinary organs | not billable |
| cheek | T20.46 | Corrosion of unspecified degree of forehead and cheek | not billable |
| chest wall | T21.41 | Corrosion of unspecified degree of chest wall | not billable |
| chin | T20.43 | Corrosion of unspecified degree of chin | not billable |
| colon | T28.7 | Corrosion of other parts of alimentary tract | not billable |
| cornea | T26.6 | Corrosion of cornea and conjunctival sac | not billable |
| dorsum of hand | T23.469 | Corrosion of unspecified degree of back of unspecified hand | not billable |
| ear | T20.41 | Corrosion of unspecified degree of ear [any part, except ear drum] | not billable |
| elbow | T22.429 | Corrosion of unspecified degree of unspecified elbow | not billable |
| epiglottis | T27.4 | Corrosion of larynx and trachea | not billable |
| esophagus | T28.6 | Corrosion of esophagus | not billable |
| eyeand adnexa | T26.9 | Corrosion of eye and adnexa, part unspecified | not billable |
| eyelid | T26.5 | Corrosion of eyelid and periocular area | not billable |
| finger | T23.429 | Corrosion of unspecified degree of unspecified single finger (nail) except thumb | not billable |
| foot | T25.429 | Corrosion of unspecified degree of unspecified foot | not billable |
| forearm | T22.419 | Corrosion of unspecified degree of unspecified forearm | not billable |
| forehead | T20.46 | Corrosion of unspecified degree of forehead and cheek | not billable |
| gastrointestinal tract NEC | T28.7 | Corrosion of other parts of alimentary tract | not billable |
| hand | T23.409 | Corrosion of unspecified degree of unspecified hand, unspecified site | not billable |
| head | T20.40 | Corrosion of unspecified degree of head, face, and neck, unspecified site | not billable |
| internal organ | T28.90 | Corrosions of unspecified internal organs | not billable |
| intestine | T28.7 | Corrosion of other parts of alimentary tract | not billable |
| knee | T24.429 | Corrosion of unspecified degree of unspecified knee | not billable |
| larynx | T27.4 | Corrosion of larynx and trachea | not billable |
| lip | T20.42 | Corrosion of unspecified degree of lip(s) | not billable |
| lung | T27.5 | Corrosion involving larynx and trachea with lung | not billable |
| mouth | T28.5 | Corrosion of mouth and pharynx | not billable |
| neck | T20.47 | Corrosion of unspecified degree of neck | not billable |
| nose | T20.44 | Corrosion of unspecified degree of nose (septum) | not billable |
| palm | T23.459 | Corrosion of unspecified degree of unspecified palm | not billable |
| pharynx | T28.5 | Corrosion of mouth and pharynx | not billable |
| rectum | T28.7 | Corrosion of other parts of alimentary tract | not billable |
| respiratory tract | T27.7 | Corrosion of respiratory tract, part unspecified | not billable |
| scalp | T20.45 | Corrosion of unspecified degree of scalp [any part] | not billable |
| scapular region | T22.469 | Corrosion of unspecified degree of unspecified scapular region | not billable |
| shoulder | T22.459 | Corrosion of unspecified degree of unspecified shoulder | not billable |
| stomach | T28.7 | Corrosion of other parts of alimentary tract | not billable |
| thigh | T24.419 | Corrosion of unspecified degree of unspecified thigh | not billable |
| throat | T28.5 | Corrosion of mouth and pharynx | not billable |
| thumb | T23.419 | Corrosion of unspecified degree of unspecified thumb (nail) | not billable |
| toe | T25.439 | Corrosion of unspecified degree of unspecified toe(s) (nail) | not billable |
| tongue | T28.5 | Corrosion of mouth and pharynx | not billable |
| tonsil | T28.5 | Corrosion of mouth and pharynx | not billable |
| trachea | T27.4 | Corrosion of larynx and trachea | not billable |
| trunk | T21.40 | Corrosion of unspecified degree of trunk, unspecified site | not billable |
| upper limb | T22.40 | Corrosion of unspecified degree of shoulder and upper limb, except wrist and hand, unspecified site | not billable |
| uterus | T28.8 | Corrosion of internal genitourinary organs | not billable |
| vagina | T28.8 | Corrosion of internal genitourinary organs | not billable |
| wrist | T23.479 | Corrosion of unspecified degree of unspecified wrist | not billable |
Corrosion abdomen, abdominal
Corrosion above elbow
| first degree | T22.539 | Corrosion of first degree of unspecified upper arm | not billable |
| left | T22.432 | Corrosion of unspecified degree of left upper arm | not billable |
| right | T22.431 | Corrosion of unspecified degree of right upper arm | not billable |
| second degree | T22.639 | Corrosion of second degree of unspecified upper arm | not billable |
| third degree | T22.739 | Corrosion of third degree of unspecified upper arm | not billable |
Corrosion ankle
| first degree | T25.519 | Corrosion of first degree of unspecified ankle | not billable |
| left | T25.412 | Corrosion of unspecified degree of left ankle | not billable |
| right | T25.411 | Corrosion of unspecified degree of right ankle | not billable |
| second degree | T25.619 | Corrosion of second degree of unspecified ankle | not billable |
| third degree | T25.719 | Corrosion of third degree of unspecified ankle | not billable |
Corrosion axilla
| first degree | T22.549 | Corrosion of first degree of unspecified axilla | not billable |
| left | T22.442 | Corrosion of unspecified degree of left axilla | not billable |
| right | T22.441 | Corrosion of unspecified degree of right axilla | not billable |
| second degree | T22.649 | Corrosion of second degree of unspecified axilla | not billable |
| third degree | T22.749 | Corrosion of third degree of unspecified axilla | not billable |
Corrosion back
Corrosion buttock
Corrosion calf
| first degree | T24.539 | Corrosion of first degree of unspecified lower leg | not billable |
| left | T24.432 | Corrosion of unspecified degree of left lower leg | not billable |
| right | T24.431 | Corrosion of unspecified degree of right lower leg | not billable |
| second degree | T24.639 | Corrosion of second degree of unspecified lower leg | not billable |
| third degree | T24.739 | Corrosion of third degree of unspecified lower leg | not billable |
Corrosion cheek
Corrosion chest wall
Corrosion chin
Corrosion dorsum of hand
| first degree | T23.569 | Corrosion of first degree of back of unspecified hand | not billable |
| left | T23.462 | Corrosion of unspecified degree of back of left hand | not billable |
| right | T23.461 | Corrosion of unspecified degree of back of right hand | not billable |
| second degree | T23.669 | Corrosion of second degree back of unspecified hand | not billable |
| third degree | T23.769 | Corrosion of third degree back of unspecified hand | not billable |
Corrosion ear
| drum | T28.91 | Corrosions of ear drum | not billable |
| first degree | T20.51 | Corrosion of first degree of ear [any part, except ear drum] | not billable |
| second degree | T20.61 | Corrosion of second degree of ear [any part, except ear drum] | not billable |
| third degree | T20.71 | Corrosion of third degree of ear [any part, except ear drum] | not billable |
Corrosion elbow
| first degree | T22.529 | Corrosion of first degree of unspecified elbow | not billable |
| left | T22.422 | Corrosion of unspecified degree of left elbow | not billable |
| right | T22.421 | Corrosion of unspecified degree of right elbow | not billable |
| second degree | T22.629 | Corrosion of second degree of unspecified elbow | not billable |
| third degree | T22.729 | Corrosion of third degree of unspecified elbow | not billable |
Corrosion extent
| less than 10 percent | T32.0 | Corrosions involving less than 10% of body surface | |
| 10-19 percent | T32.10 | Corrosions involving 10-19% of body surface with 0% to 9% third degree corrosion | |
| 20-29 percent | T32.20 | Corrosions involving 20-29% of body surface with 0% to 9% third degree corrosion | |
| 30-39 percent | T32.30 | Corrosions involving 30-39% of body surface with 0% to 9% third degree corrosion | |
| 40-49 percent | T32.40 | Corrosions involving 40-49% of body surface with 0% to 9% third degree corrosion | |
| 50-59 percent | T32.50 | Corrosions involving 50-59% of body surface with 0% to 9% third degree corrosion | |
| 60-69 percent | T32.60 | Corrosions involving 60-69% of body surface with 0% to 9% third degree corrosion | |
| 70-79 percent | T32.70 | Corrosions involving 70-79% of body surface with 0% to 9% third degree corrosion | |
| 80-89 percent | T32.80 | Corrosions involving 80-89% of body surface with 0% to 9% third degree corrosion | |
| 90 percent or more | T32.90 | Corrosions involving 90% or more of body surface with 0% to 9% third degree corrosion |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources