Neurology & Pain Management Coding Alert

Hint: In many cases, you’ll be coding out to the 6^th character.

ICD-10-CM coding for migraine may seem simple on the surface, but in reality, this condition trips up even the most seasoned coders. Why? Because it requires you to know such factors as whether the patient’s diagnosis is chronic or acute, whether the patient has aura, and even where the symptoms are occurring.

To get a firm handle on how to report migraine diagnoses, check out four coding strategies that will ensure you collect for every migraine encounter.

1. The Easy Part: The First 3 Characters

When your provider sees a patient with migraine, you’ll look to the G43.- (Migraine) section of the ICD-10-CM code set. But next to the G43.- code, you’ll see the symbol “4^th,” which means that you cannot submit a claim for this code without also adding a 4^th character.

2. Move on to 4^th Character Concerns

In ICD-10-CM, the migraine codes are classified to category G43.-, with no fewer than 13 options to choose from for your 4^th character. Check out the options below, along with tips on determining when to use them:

• G43.0- (Migraine without aura): You’ll select a code from this category if the patient doesn’t experience a warning sign prior to the migraine known as an “aura,” which typically involves visual disturbances such as seeing blind spots, seeing “stars,” having visual hallucinations, or having trouble seeing.

• G43.1- (Migraine with aura): If the documentation indicates that the patient had aura prior to their migraine attack, you’ll report a code from this section. Keep in mind that the documentation should mention aura or describe it (for example, “patient saw zigzag patterns for 30 minutes prior to the migraine attack onset”).

• G43.4- (Hemiplegic migraine): This is a migraine with weakness, numbness, or paralysis that affects only one side of the body. Some people think they may be having a stroke when they experience a hemiplegic migraine.

• G43.5- (Persistent migraine aura without cerebral infarction): A cerebral infarction is a severe situation, also referred to as an ischemic stroke. It may occur when a blood clot causes a blocked artery in the brain, and it must be confirmed with imaging. If imaging does not confirm cerebral infarction in someone with persistent migraine aura, you can report this code.

• G43.6- (Persistent migraine aura with cerebral infarction): If imaging confirms that the patient is experiencing a cerebral infarction along with ongoing migraine aura, report a code from G43.6-.

• G43.7- (Chronic migraine without aura): Most payers define a chronic migraine attack as lasting 15 days or more per month without medication overuse. In addition, the patient must have experienced additional symptoms eight days a month for at least three months, including moderate to severe headaches that pulsate or occur on one side of the head, which may or may not cause vomiting or nausea. Make sure patients are not experiencing aura when reporting this code.

• G43.8- (Other migraine): If your patient’s migraine can’t be described using the other codes in this category, G43.8- may apply. For instance, if the patient experiences a menstrual migraine, you’ll look to this section.

• G43.9- (Migraine, unspecified): In cases where the provider didn’t document enough details to confirm whether or not the condition fits into one of the other categories, you can select a code from this section.

• G43.A- (Cyclical vomiting): When the patient has recurring vomiting episodes along with migraine symptoms, they may be experiencing cyclical vomiting. If the provider confirms this diagnosis, select a code in the G43.A- range.

• G43.B- (Ophthalmoplegic migraine): This condition involves such severe migraine headaches that the patient experiences temporary paralysis or weakness of their eye muscle(s). Typically, the documentation will include the fact that the patient underwent imaging to rule out a stroke or aneurysm.

• G43.C- (Periodic headache syndromes in child or adult): Some conditions may not fit into other categories, but they affect patients periodically. These syndromes may fit into this category.

• G43.D- (Abdominal migraine): In this type of migraine, the patient experiences recurrent, severe episodes of stomach pain but not head pain. This condition traditionally impacts pediatric patients.

• G43.E- (Chronic migraine with aura): Some chronic migraine patients experience aura. In these cases, you’ll report a code from the G43.E- range.

3. The 5^th Character Counts

In the codes above, you’ll notice that every one of them features a “5^th” symbol, which means you cannot report any of them to only the 4^th character. To select the appropriate 5^th character, you’ll need to know whether the migraine is not intractable (0) or intractable (1).

Definition: Intractable migraines are those that don’t subside, whether or not the provider offers treatment.

When reviewing documentation, the following terms are considered equivalent to intractable:

• Pharmacoresistant
• Pharmacologically resistant
• Treatment resistant, refractory
• Medically refractory
• Poorly controlled

Best bet: If you see any of these terms in the encounter notes for a migraine patient, then they likely have an intractable migraine. When in doubt, consult with the provider who treated the patient on a final not intractable/intractable decision.

4. You’ll Often Need a 6^th Character, Too

Most migraine ICD-10-CM codes also require you to select a 6^th character to indicate the presence or absence of status migrainosus. Status migrainosus refers to a migraine that has lasted longer than 72 hours.

Exception: You won’t need a 6^th character for several categories of migraine. The following categories only require 5 characters: G43.A-, G43.B-, G43.C-, G43.D-, and G43.E-.

Torrey Kim, Contributing Writer, Raleigh, NC