T85.391A vs T85.391D

T85.391A (Other mechanical complication of prosthetic orbit of left eye, initial encounter) compared with T85.391D (Other mechanical complication of prosthetic orbit of left eye, subsequent encounter), from the official CMS tabular data. T85.391A and T85.391D code the same injury at a different phase of treatment.

Relationship

Review

Encounter relationship

T85.391A

Initial encounter

Other mechanical complication of prosthetic orbit of left eye, initial encounter

↔

T85.391D

Subsequent encounter

Other mechanical complication of prosthetic orbit of left eye, 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. T85.391A and T85.391D 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

	T85.391AOther mechanical complication of prosthetic orbit of left eye, initial encounter	T85.391DOther mechanical complication of prosthetic orbit of left eye, subsequent encounter
Billing status	Billable	Billable
Classification	S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)	S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)
Definition	Other mechanical complication of prosthetic orbit of left eye, initial encounter is a billable ICD-10-CM diagnosis code (T85.391A).	Other mechanical complication of prosthetic orbit of left eye, subsequent encounter is a billable ICD-10-CM diagnosis code (T85.391D).
7th character	The appropriate 7th character is to be added to each code from category T85	The appropriate 7th character is to be added to each code from category T85
Use additional code	code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5) code(s) to identify the specified condition resulting from the complication code to identify devices involved and details of circumstances (Y62-Y82)	code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5) code(s) to identify the specified condition resulting from the complication code to identify devices involved and details of circumstances (Y62-Y82)

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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