Concussions are one of the few diagnoses that touch nearly every kind of practice Mediclaim supports. An EMS crew transports a patient after a fall, an urgent care clinic evaluates a teenager after a sports collision, a neurology practice follows a patient whose headaches and dizziness never went away, and a dental office treats a fractured tooth that came from the same blow to the face. Each one of those encounters carries a different coding story, and the details — loss of consciousness, encounter type, and what happens weeks later — decide whether the claim pays.
This guide walks through the ICD-10-CM codes used most often for concussion and mild traumatic brain injury, the 7th-character rules that trip up billing teams, and the documentation that needs to be in the chart before the claim goes out.
The Core Code Family: S06.0X Concussion
Concussion lives in subcategory S06.0X. The 5th and 6th characters are fixed; what changes the code is the loss of consciousness (LOC) documented at the time of injury, and the 7th character for the type of encounter.
Loss of Consciousness Variants
S06.0X0- — Concussion without loss of consciousness
S06.0X1- — Concussion with loss of consciousness of 30 minutes or less
S06.0X9- — Concussion with loss of consciousness of unspecified duration
S06.0XA- — Concussion with loss of consciousness status unknown
Note that the first four characters plus the LOC digit (for example, S06.0X0) are not billable on their own — a 7th character is always required.
7th Characters: A, D, and S
A (initial encounter) — used while the patient is receiving active treatment. This is not the same as the "first visit." An urgent care visit, an ED evaluation, and a neurology consult that directs the treatment plan can all be "A."
D (subsequent encounter) — routine care during the healing or recovery phase, after active treatment is complete.
S (sequela) — late effects of the concussion, coded after the condition that resulted from it.
Real examples of fully billable codes:
S06.0X0A — Concussion without loss of consciousness, initial encounter
S06.0X1A — Concussion with loss of consciousness of 30 minutes or less, initial encounter
S06.0X9A — Concussion with loss of consciousness of unspecified duration, initial encounter
S06.0XAA — Concussion with loss of consciousness status unknown, initial encounter
S06.0X0D — Concussion without loss of consciousness, subsequent encounter
S06.0X0S — Concussion without loss of consciousness, sequela
Documentation must-have: the provider note should state whether the patient lost consciousness and, if so, for how long. When the patient or bystanders genuinely don't know, "LOC status unknown" (S06.0XA-) is the more accurate choice than guessing — and it is more defensible than defaulting to "without LOC."
Symptom Codes: When to Add Them and When Not To
Common concussion symptoms have their own codes, but they are generally integral to the diagnosis and shouldn't be added once a concussion code is assigned. Use them when the diagnosis is not yet established or when the provider documents a symptom that isn't routinely part of the condition.
R51.9 — Headache, unspecified
R42 — Dizziness and giddiness
R11.0 — Nausea
R41.0 — Disorientation, unspecified
R41.3 — Other amnesia
R55 — Syncope and collapse
If a head injury evaluation rules out a concussion or the provider hasn't confirmed one, S09.90XA (Unspecified injury of head, initial encounter) or S00.93XA (Contusion of unspecified part of head, initial encounter) may more accurately reflect the encounter than a concussion code.
When It's More Than a Concussion
S06 is a large category, and a head injury work-up can find more than a concussion. Intracranial injuries are coded separately, with their own LOC options and 7th characters, for example:
S06.5X0A — Traumatic subdural hemorrhage without loss of consciousness, initial encounter
S06.360A — Traumatic hemorrhage of cerebrum, unspecified, without loss of consciousness, initial encounter
S06.9X0A / S06.9X9A — Unspecified intracranial injury, without LOC / with LOC of unspecified duration, initial encounter
When imaging shows a more serious injury, that diagnosis — not the concussion code — should lead the claim. Coders should review the radiology result before finalizing diagnosis codes for any head-injury encounter.
Post-Concussion Syndrome and Persistent Symptoms (Neurology's Territory)
When symptoms persist after the acute phase, the coding changes.
F07.81 — Postconcussional syndrome. Used when the provider documents the syndrome (persistent headache, dizziness, cognitive and sleep complaints). Under ICD-10-CM conventions, F07.81 is not reported together with a current concussion code (S06.0X-).
G44.319 / G44.311 — Acute post-traumatic headache, not intractable / intractable
G44.329 / G44.321 — Chronic post-traumatic headache, not intractable / intractable
G44.309 / G44.301 — Post-traumatic headache, unspecified, not intractable / intractable
Z87.820 — Personal history of traumatic brain injury (for patients with a resolved injury that is relevant to current care)
Documentation must-have: "post-traumatic headache" must be linked to the injury in the provider's note, and the intractable vs. not intractable distinction needs to be documented. Neurology practices that bill G44.3- headache codes with no connection to the injury in the chart invite medical necessity questions.
External Cause and Place Codes
Many payers — especially auto, workers' compensation, and liability carriers — look for external cause information to determine who is responsible for the claim. These codes are secondary and are never reported as a primary diagnosis.
W18.30XA — Fall on same level, unspecified, initial encounter
Y93.66 — Activity, soccer
Y92.322 — Soccer field as the place of occurrence of the external cause
For concussions from sports, falls, or vehicle collisions, capturing the external cause at intake — not after a denial — keeps the claim from being held for accident details.
Cross-Specialty Notes
EMS agencies: Transport claims need a diagnosis that supports medical necessity for the level of service. A documented head strike, LOC, altered mental status, and mechanism of injury belong in the run report so the receiving diagnosis and the transport narrative tell the same story.
Urgent care: Most concussion visits are initial encounters (7th character A). Document LOC, symptoms, any imaging decision, and return-to-play or return-to-school instructions.
Neurology: Follow-up visits for persistent symptoms may move from S06.0X-D to F07.81 and G44.3- codes. The change should match the provider's documented clinical picture.
Dental: Facial trauma that involves a fractured tooth (S02.5XXA, Fracture of tooth (traumatic), initial encounter for closed fracture) may also warrant a head injury evaluation. Dental practices don't diagnose concussion, but a note recommending medical evaluation helps the patient and supports coordination with medical billing.
Where Concussion Claims Most Often Get Denied
1. Missing or incorrect 7th character. S06.0X0 without a 7th character is an invalid code, and the claim is rejected at the front end. Equally common: using "A" for every visit or "D" for an active-treatment visit.
2. LOC guessed rather than documented. Billing "without LOC" when the chart doesn't say can conflict with EMS or ED records. Documentation and code should match across all providers involved in the case.
3. Symptom codes stacked on top of a concussion diagnosis. Adding R51.9 and R42 to S06.0X0A usually adds nothing and can draw bundling or edit flags.
4. Post-concussion syndrome billed with an active concussion code. F07.81 and S06.0X- describe different phases. Billing both on the same claim is a common edit trigger.
5. Missing external cause or accident details. Auto and liability payers often hold or deny claims until accident information is on file.
Action step: Pull your last 60 days of head injury claims and check three things — whether every S06 code has a valid 7th character, whether LOC status is documented in the chart, and whether any claim lists F07.81 and S06.0X- together.
FAQ
What is the ICD-10 code for a concussion?
Concussion codes begin with S06.0X and require a loss of consciousness digit and a 7th character. For example, S06.0X0A is concussion without loss of consciousness, initial encounter, and S06.0X1A is concussion with loss of consciousness of 30 minutes or less, initial encounter.
What does the 7th character mean on a concussion code?
The 7th character shows the type of encounter: A for active treatment, D for subsequent (routine healing-phase) care, and S for sequela, or late effects. It is not based on whether it's the patient's first visit.
When should post-concussion syndrome (F07.81) be used instead of a concussion code?
Use F07.81 when the provider documents postconcussional syndrome — persistent symptoms after the acute injury. It generally isn't reported together with a current concussion code (S06.0X-). Associated post-traumatic headache can be coded additionally with G44.3-.
What if the patient doesn't know whether they lost consciousness?
Use the "LOC status unknown" option (S06.0XA-) rather than assuming. The provider's note should record that LOC status couldn't be determined.
How does Mediclaim Services help with head injury and concussion billing?
Mediclaim Services reviews diagnosis coding, 7th-character accuracy, and documentation for urgent care, EMS, neurology, and dental claims, and works denials in Tebra so head-injury claims get paid the first time.
Getting Concussion Claims Right the First Time
Concussion coding rewards precision: the right LOC variant, the right 7th character, and a clean handoff from the acute diagnosis to post-concussion codes when symptoms linger. With the right documentation habits in place, these claims can move through payers as cleanly as any other.
At Mediclaim Services Inc., we manage medical billing for practices treating dental, EMS, neurology, and urgent care patients — including the head injury cases that cross all four. We use Tebra's billing platform to keep diagnosis coding, claim submission, and denial resolution running smoothly.
Contact Mediclaim Services to schedule a free billing audit
Ready for a closer look at your head injury and concussion coding? Contact Mediclaim Services today for a free billing review.
