T20.612A vs T20.612D

T20.612A (Corrosion of second degree of left ear [any part, except ear drum], initial encounter) compared with T20.612D (Corrosion of second degree of left ear [any part, except ear drum], subsequent encounter), from the official CMS tabular data. T20.612A and T20.612D code the same injury at a different phase of treatment. MedCoder-derived

Relationship

Review

Encounter relationship

T20.612A

Initial encounter

Corrosion of second degree of left ear [any part, except ear drum], initial encounter

↔

T20.612D

Subsequent encounter

Corrosion of second degree of left ear [any part, except ear drum], subsequent encounter

Same underlying diagnosis, different encounter phase.

The 7th character records the phase of care for the encounter being coded, so a single encounter takes one of these characters, not several. Review whether both phases belong on the same episode of care.

Source: ICD-10-CM Official Guidelines, Section I.C.19.a

Can these codes be reported together?

Same injury, other encounter phase. T20.612A and T20.612D code the same injury at a different phase of treatment, set by the 7th character.

The 7th character records the type of care given at the encounter being coded (ICD-10-CM Official Guidelines, Section I.C.19.a), so one encounter takes one of these, not both.

Side by side

	T20.612ACorrosion of second degree of left ear [any part, except ear drum], initial encounter	T20.612DCorrosion of second degree of left ear [any part, except ear drum], subsequent encounter
Billing status	Billable	Billable
Classification	S00-T88 — Injury, poisoning and certain other consequences of external causes	S00-T88 — Injury, poisoning and certain other consequences of external causes
Definition	Corrosion of second degree of left ear [any part, except ear drum], initial encounter is a billable ICD-10-CM diagnosis code (T20.612A).	Corrosion of second degree of left ear [any part, except ear drum], subsequent encounter is a billable ICD-10-CM diagnosis code (T20.612D).
7th character	The appropriate 7th character is to be added to each code from category T20	The appropriate 7th character is to be added to each code from category T20
Includes	burns and corrosions of first degree [erythema] burns and corrosions of second degree [blisters][epidermal loss] burns and corrosions of third degree [deep necrosis of underlying tissue] [full- thickness skin loss]	burns and corrosions of first degree [erythema] burns and corrosions of second degree [blisters][epidermal loss] burns and corrosions of third degree [deep necrosis of underlying tissue] [full- thickness skin loss]
Use additional code	external cause code to identify place (Y92) code from category T31 or T32 to identify extent of body surface involved	external cause code to identify place (Y92) code from category T31 or T32 to identify extent of body surface involved
Code first	(T51-T65) to identify chemical and intent	(T51-T65) to identify chemical and intent

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Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources