Long-Term Care Survey Alert

Basic Training:

Watch Out For Code Extensions

All ICD-10 diagnosis codes have between 3 and 7 characters. Here’s how they break down (and don’t forget the decimal point between characters 3 and 4):

Use the first three characters to define the category of diagnosis:

1st Character — alpha component
2nd Character — numeric
3rd Character — numeric

Example:

Dementia unspecified, F03

Use characters 4 — 6 to define etiology, anatomical site, and severity of the diagnosis.

4th Character — alpha or numeric
5th Character — alpha or numeric
6th Character — alpha or numeric

Examples:

F03.90 Dementia (degenerative (primary) (old age) (persisting)

F03.91 — Dementia (degenerative (primary) with aggressive behavior

Alzheimer’s specific codes, however, would begin with G30.

7th Character — extension, alpha or numeric

ICD-10 uses code extensions for, among other uses, to identify the encounter for injuries and external causes, initial encounter (A), subsequent encounter (D), or sequela (S).

Example:

W06.XXXD — Subsequent encounter for a fall from a bed

[Note: Xs are used as placeholders if a code does not require digits 3-6 for specificity. That is, the extension must always be placed as the seventh character.]