Coding Epilepsy

Epilepsy is a neurological disorder where patients suffer from seizures. These seizures are a result of excessive and abnormal cortical nerve cell activity in the brain. The cause of epilepsy in many patients may be unknown, but it can develop from brain injury, stroke, brain cancer, and drug or alcohol abuse.

Seizures present differently based on the person’s age and the part of the brain involved. The most common seizures (about 60%) are “convulsive” and the remaining are “non-convulsive,” such as an “Absence Seizure,”  which is a decreased level of consciousness that lasts about 10 seconds.

Convulsive seizures are further broken down with the majority (2/3) being “focal seizures” and the rest (1/3) are “generalized.”

Focal seizures often give the patient a warning, called an “aura,” such as a vision, a smell, a sound, or some other psychic or motor function that is felt by the person before it begins.

There are 6 main types of generalized seizures:

  1. Tonic-clonic
  2. Tonic
  3. Clonic
  4. Myoclonic
  5. Absence
  6. Atonic

Seizure codes (G40.-) are chosen based on whether the seizure is documented as with or without “status epilepticus,” and whether they are “intractable” or “non-intractable.”

Status epilepticus is a life threatening condition where the brain is in a state of persistent seizure lasting longer than 5 minutes. It is considered a medical emergency.

Intractable = hard to control. Seizures fail to come under control with treatment. Also called “uncontrolled” or “refractory.”

Non-intractable = not hard to control. Seizures are controlled with treatment.

Note the different includes between Epilepsy codes and Convulsion codes in ICD-10-CM in the below examples:

G40.909 Epilepsy, unspecified, not intractable, without status epilepticus

  • Epilepsy NOS
  • Epileptic convulsions NOS
  • Epileptic fits NOS
  • Epileptic seizures NOS
  • Recurrent seizures NOS
  • Seizure disorder NOS

R56.9 Unspecified convulsions

  • Convulsion disorder
  • Fit NOS
  • Recurrent convulsions
  • Seizure(s) (convulsive) NOS


Brian Boyce, BSHS, CPC, CPC-I, CRC, CTPRP is an AAPC-approved PMCC medical coding instructor, and ICD-10-CM trainer and the author of the AAPC CRC® curriculum. He has specialized in risk adjustment from the very beginnings of these models being utilized and has assisted large and small clients nationally. He has special interest in ethics, patient safety, disease management, and management and leadership of people. Brian is a veteran of Desert Storm, where he served on active duty with the US Air Force with a job specialty of Aeromedical Evacuation. He went into physician practice management and medical coding after an honorable discharge. He is the CEO of ionHealthcare® LLC, a company that specializes in healthcare consulting, risk adjustment coding, management & support services. For additional inquiries contact ionHealthcare® at