Is G43 a billable ICD-10-CM code?

No. G43 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does G43 sit in the tabular list?

Diseases of the nervous system (G00-G99), in the block Episodic and paroxysmal disorders (G40-G47).

What cannot be coded together with G43?

G43 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

G43

G43 — Migraine

Non-billable headerICD-10-CM

G43 is a non-billable header ICD-10-CM code for migraine. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

lower half migraine (G44.00)

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

headache NOS (R51.9)
headache syndromes (G44.-)

Use additional code

Add a secondary code to capture the detail described below.

code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Notes

Additional guidance from the ICD-10-CM tabular list.

the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically) and poorly controlled

Other codes that can never be billed with G43

These codes carry an Excludes1 note pointing at G43. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading G43 alone.

R11Nausea and vomiting
R11.15Cyclical vomiting syndrome unrelated to migraine
G43.0Migraine without aura
G43.1Migraine with aura
G43.7Chronic migraine without aura
G43.EChronic migraine with aura

Risk adjustment

G43 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead G43

13 child codes. Green means billable.

Questions about G43

Is G43 a billable ICD-10-CM code?: No. G43 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does G43 sit in the tabular list?: Diseases of the nervous system (G00-G99), in the block Episodic and paroxysmal disorders (G40-G47).
What cannot be coded together with G43?: G43 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.