Migraine ICD 10: Codes, G43.909 & Billing Guide

Migraine ICD 10 coding is done under the G43 category. G43.909 indicates migraine, unspecified, not intractable, without status migrainosus. Other codes in the G43 category may be assigned for chronic migraine, migraine aura, migraine with treatment resistance, etc. Status migrainosus is covered under the G43.7 code. The G43 category is a category, not a complete billable diagnosis code.

A chart that simply states “migraine” leaves a lot of questions, whereas one that states “chronic migraine with aura” makes the documentation and code selection a lot clearer. This guide gives you the quick lookup first, and then covers the more in-depth explanations for code selection, documentation, and claim review.

Migraine ICD 10 quick-reference codes

For a quick answer, start in the left column with the documented diagnosis. These examples provided are of complete codes. The next section provides example codes of more inclusive groups and families.

“Billable” refers to a diagnosis code being recorded for receipt of payment. The use of a diagnosis code in no way implies the payer will accept and reimburse for the service, medication, or procedure. Coverage is still dependent on service, benefit terms, medical documentation and policy.

Keep the entire code in your reference sheet. G43.019 and G43.009 look alike, but only one identifies intractability, the other does not. A misplaced comma can change what diagnosis code you report to the payer.

The G43 family: categories versus complete codes

The U.S. version of ICD-10-CM is different from WHO’s version of ICD-10. Although they share similarities, their category structures are not mutually exclusive. As a result, ICD-10 codes assigned outside the U.S. may not be relevant for U.S. diagnosis claims.

This is illustrated in an online article that provided ICD-10 codes for status migrainosus (G43.2) and complicated migraine (G43.3). These are not the appropriate U.S. sub-categories and should not be used to complete a diagnosis claim. Also, do not attempt to fill in perceived numbering gaps by importing codes from other versions of ICD-10 that may be published elsewhere.

The family overview below, provides a comprehensive overview of the alphabetic and numeric branches of the ICD-10 classification. A list that stops at G43.9 and omits G43.A through G43.E, is not adequate for U.S. migraine coding.

Read both the label and the final characters

The example shows how several migraine branches have four different combinations: not intractable (without status), not intractable (with status), intractable (with status), and intractable (without status). The following example illustrates that pattern.

Do not generalize this example to create a rule for all headache codes. For example, the distinction for abdominal migraine by intractability in codes G43.D0 and G43.D1 is made without the use of a separate status character. Review the full descriptor for each code, instead of assuming that all codes have six characters.

Aura, intractability, and status describe different things

They describe different things. Aura describes a pattern of symptoms. Intractability describes resistance to treatment. Status Migrainosus describes a migraine complication. Aura, intractability, and status migrainosus are not interchangeable.

With Aura vs Without Aura

Aura can involve visual, sensory, or speech/language symptoms. It can occur before or during a headache, and some people can experience aura without a headache. Describing aura as a warning prior to the headache pain is too restrictive.

Light sensitivity is different. Someone may prefer a dark room during an attack without having migraine with aura. Blurred vision, or a generalized statement such as “visual migraine,” requires a clinical judgment rather than assigning a code from G43.1 automatically.

A note to the provider identifies a symptom, when it occurred, and the type of migraine that the provider believes it to be. The coder’s job is to interpret the note, and follow the provider’s documentation and classification instructions. Symptom lists do not grant the coder the ability to independently diagnose aura.

Intractable vs Not Intractable

An intractable migraine is one that is unmanageable. Terms such as refractory, treatment resistant, pharmacologically resistant, or poorly controlled may carry coding significance, if documented by the provider and supported by the classification instructions.

Severe pain alone does not establish intractability. Neither does an emergency visit, frequent attacks, nor does a treatment stating a medication was given. The history of treatment explains the migraine type; however, a list of treatment medications does not allow the coder to diagnose aura.

Do not implement “two failed medications” or some other fixed count as a universal diagnosis coding rule. A payer may require a medication trial for a particular treatment; this requirement is a separate coverage determination from coding.

With or without status migrainosus

ICHD-3 defines status migrainosus as a prolonged disabling migraine attack, usually of more than 72 hours duration, with other requirements and qualifications. The duration threshold is meaningful clinical context, not a substitute for a coder to diagnose based on a calendar.

A patient may say they experienced multiple attacks over a 4 day period, and not report a single qualifying prolonged attack. It is the clinician’s responsibility to review the evidence and determine if the multiple attacks represent a continuation of the same episode. The clinician must evaluate the surrounding context (if any), symptoms, and consider potential alternative causes and explain their reasoning in the documentation.

G43.001 includes status migrainosus without intractability; G43.019 includes intractability without status. Reading these two codes in combination discourages another common mistake, assuming every long duration migraine is resistant to treatment.

Chronic migraine ICD 10: G43.7 and G43.E

A note that says “migraines” doesn’t show the degree to which the symptoms interfere in the patient’s day-to-day life. Chronic migraine is defined as headaches occurring on at least 15 days of the month for at least three months with migraine features on at least 8 of those days. Keeping track of headache frequency and symptoms and how well different treatments work can give the clinician a more complete picture. This also helps the care team if the patient is receiving Chronic Care Management Services. The care team can then better track the patient’s progress, identify any gaps in care, and take action for follow-up.

The clinician is responsible for establishing the diagnosis and a headache diary can be used in support of that, but coders can not use diaries to assign a diagnosis of chronic migraine when the clinician hasn’t given it. If assessment is unclear or different parts of the record conflict, ask the clinician to clarify before assigning a code.

Choose the correct chronic branch

G43.709 is a specific code for chronic migraine and does not represent a universal code for chronic migraine. A code G43.109 represents a chronic migraine with aura diagnosis and is also not a universal code for chronic migraine. G43.E is a code for chronic migraine with aura and should be used with G43.709.

This helpful chronic migraine note distinguishes total headache days from days with migraine features. It captures how long this pattern has been occurring, describes how this has impacted the patient’s ability to engage in daily activities, captures the patient’s treatment history, and notes the clinical team’s current assessment.

Keep baselines and treatment responses distinct

It is useful to distinguish the patient’s prior status from the current situation in subsequent notes. A statement such as, “Headache days improved,” is more informative if we understand over what time period this was the case, and what was the intervention that caused the improvement.

Just because the patient’s total number of headache days has reduced, we cannot automatically remove the diagnosis of chronic migraine. Just the same, we cannot keep a copied diagnosis indefinitely without checking the provider’s current assessment. The goal of the chart should be to capture a coherent clinical story as opposed to documenting unrelated numbers at each visit.

Prior authorization from payers may require additional information beyond the diagnosis code. An adequate ICD-10 code for G43 cannot replace missing information about the patient’s documented headache frequency or a trial of a migraine treatment if the payer’s policy requires this documentation.

Menstrual, abdominal, and other specific migraine types

Some presentations of migraine require specialized branches. For example, rather than starting with the clinician’s diagnosis of migraine with or without aura, you can consider other potential causes of an individual’s symptoms (e.g. aseptic meningitis, viral meningitis, etc.) and work backwards to determine if migraine is the correct diagnosis.

Menstrual migraines: G43.82 and G43.83

G43.82 is the code for menstrual migraine that is not intractable. The code for menstrual migraine that is intractable is G43.83. A complete code requires an additional character for both codes.

Menstrual migraine is coding of migraine that occurs during a patient’s menstrual cycle. To determine the relationship between the migraine and the patient’s menstrual cycle, use the following guidelines. Review the Tabular instructions for any additional information or coding requirements relevant to the documented situation.

Abdominal Migraine: G43.D

There are two complete ICD-10-CM codes for abdominal migraine: one for migraine abdominal, not intractable, G43.D0, and one for migraine abdominal, intractable, G43.D1. There is no code to specify status migrainosus for either code.

Abdominal pain, nausea, or vomiting, alone, do not warrant a diagnosis of abdominal migraine. A clinician must evaluate the symptoms and provide a diagnosis. If abdominal migraine is not confirmed during an outpatient visit, an appropriate code for abdominal pain ICD-10 may be assigned for abdominal pain of documented location, and other, documented, features. Other symptoms may be coded, according to the outpatient coding rules, rather than code for a suspicion of a migraine, if this is the case.

Hemiplegic Migraine: G43.4

G43.419 means hemiplegic migraine, intractable, without status migrainosus. It does not mean chronic migraine without aura, as one erroneous competitor states.

Motor weakness, in this case hemiplegia, requires a thorough clinical assessment. Coders should not make any assumptions regarding hemiplegic migraine based on a complaint of weakness. New or sudden weakness or speech difficulty requires an urgent evaluation rather than reassuring the patient/family based on the migraine history.

Persistent aura and less familiar branches

Cerebral infarction is ruled out when a patient has a migraine with aura that persists beyond 60 minutes. This condition is reported in ICD-10 under G43.5 and G43.6. This distinction makes a significant difference between the two codes.

Cyclical vomiting as part of a migraine attack is reported in G43.A; ophthalmoplegic migraine, in G43.B; and periodic syndromes of migraine headache in the child and adult, in G43.C. The classification labels describe very specific symptoms; therefore, ordinary vomiting, eye pain, or recurrent headaches do not qualify for those codes.

When the terminology used in the clinical description does not exactly match a classification label, a diagnosis should be confirmed by consulting the Alphabetic Index and Tabular List. Online searches may assist in identifying terminology, but an official classification of a disease would need to be consulted to determine whether a diagnosis is verified.

Migraine versus headache codes: avoid the wrong family

“Headache” and “migraine” are not equivalent diagnoses. The assignment of the correct code is based on what has been established for the visit, and not solely on the location of the pain or the subjective assessment of the patient regarding the level of pain.

G44.x in general means headache due to tension. It encompasses several types of headache disorders. G44.2 is the tension-type branch. This distinction helps prevent the broad lookup of a headache code from resulting in an incorrect claim code.

R51.9 versus G43.909

R51.9 captures an unspecified headache symptom. G43.909 captures a diagnosis of migraine with the characteristic described in the descriptor. The two do not describe the same level of diagnostic confidence.

In an outpatient note, if there is no definitive diagnosis, and the term “possible migraine” is used, the diagnosis should not be treated as confirmed. The documented symptoms should be reviewed, along with the rules for reporting from outpatient settings. The same is not true of inpatient discharge rules for uncertain diagnoses.

Once migraine has been established, a generic headache code should not be added to restate the symptom. Additional symptoms should be reported, along with other relevant conditions, as long as the instructions are reviewed.

G43.909 is useful when it matches the record

Not specifying a migraine code is not always poor coding. It could be the best code to represent the information known at the time. It is not restricted by a first-visit rule, or a limit on the number of follow-up codes.

What is relevant is whether the record provides more specific information. If the record documents a migraine with aura, and the code requested states unspecified migraine, the claim loses documentation of migraine with aura. If the record only states migraine, unspecified, and no supporting documentation is available to justify the specificity, lack of specificity is not an improvement.

Repeated vague documentation could warrant a documentation improvement discussion. Treatment decisions often depend on the subtype of the migraine. If unspecified migraine codes are repeatedly submitted and the payor audits all claims, that is not an improvement.

A key review is whether migraine is documented. Does the provider specify type? Are there conflicting assessments? Is the requested service without supporting evidence? Each identifies a next step, and often, a diagnosis is not needed to identify the next step.

A practical migraine ICD 10 documentation workflow

The best way to improve workflow is to separate diagnosis review from coverage review. When the staff must complete the coding decision first, then examine the coverage requirements, staff may be tempted to choose the diagnosis that is linked to the policy coverage, rather than choosing the most appropriate diagnosis.

1. Read the Assessment

A persistent problem may lead to an incorrect coding decision. It is important to read the assessment to determine if the physician has evaluated the migraine or other headaches. If a patient has chronic migraine with aura and the assessment says migraine without aura, you would not resolve this by choosing the code that pays the best.

2. Look for Established Types of Migraine

There are a number of different subtypes of migraine. You will need to determine if the migraine is chronic, hemiplegic, menstrual, or another established subtype. Then, you will need to determine if the migraine is accompanied by an aura and/or is intractable and/or status migrainosus.

3. Review the Tabular List

Look for the term in the Alphabetic Index and verify the code and any guidelines in the Tabular List. It is always important to look beyond the initial search results.

4. Clarify the Ambiguity

A request for clarification might state, “Please provide documentation to clarify the type of migraine addressed in this encounter if it is different than what is documented in the assessment and plan.” The purpose of the request is to understand the type of migraine addressed, not to ask for documentation to support that a different type of migraine was addressed to support coverage of the procedure. If you feel the initial query was inappropriate, you may deny the request for clarification.

5. Check the service separately

After choosing the appropriate diagnosis, review authorization, procedure reporting, drug units, and payer documentation requirements as applicable. The code answers the question, “what condition was reported?” The other checks answer the question, “was the service billed correctly?”

Useful Provider Checklist

Mark the information that actually applies:

• Type of migraine was assessed and the status of aura.
• Number of headache and/or migraine feature days. Relevant for assessing chronicity.
• How long a particular symptom pattern has been in place and how long the current attack has been in place.
• Treatments tried and intolerance or contraindications.
• Functional impact and reason for the planned service.
• Other conditions, if relevant, that also impact management.

Checklists should prompt the relevant information and not preselect positive information. Language such as “intractable” or “with status migrainosus” creates a misleading appearance of a clinical assessment that may not have been made.

Three realistic coding scenarios

These cases are purely illustrative and are not based on actual patients or records. Each demonstrates the significance of the documentation of the provider and the code and does not require the coder to generate a diagnosis from the symptoms.

Scenario 1: Routine follow-up without aura

A patient returns for medication follow-up. The clinician documents the diagnosis migraine without aura and not intractable and not status migrainosus. The note describes separate attacks with relief between the episodes and a treatment response that is consistent with the assessment.

Code: G43.009

The main point is, G43.019, adds intractability that has not been documented. G43.909, discards the documented without aura classification. The visit’s assessment and management code requires an independent evaluation as well.

Scenario 2: Chronic migraine with aura and treatment resistance

A patient has been documented to have a headache for a minimum of 18 days per month for the last five months, of which 10 days were migraine headaches. After reviewing the patient’s history and treatment, the clinician diagnosed the patient with chronic migraine with aura and intractable, without status migrainosus.

Code: G43.E19

The coder uses the clinician’s diagnosis, rather than forming their own interpretation of the counts. The team independently evaluates if the record contains the frequency, medication history, and other evidence necessary for the relevant plan in order to authorize treatment.

Scenario 3: Prolonged attack assessed as status migrainosus

A patient has a prolonged debilitating attack lasting greater than 72 hours. After evaluation, the clinician documents migraine without aura, intractable, with status migrainosus.

Code: G43.011

Duration alone is not sufficient for the coder to determine status. In the provided example, the clinician has evaluated and documented it. In the example where the provider documented “a headache for four days,” clarification or more explicit symptom documentation may be appropriate, depending on the clinician’s final assessment and judgment in the case.

Common mistakes and the correction that matters

Submitting a parent category

G43, G43.0, and G43.7 are sometimes used in conjunction with specific codes to describe complete reportable diagnoses. Expand to the appropriate complete code. While a category appearing in a payer article does not necessarily mean that it can be submitted without its required characters, it could mean the description of the category is acceptable for reimbursement purposes.

Using the pain score to determine intractability

While it is true that a pain score of 10 may indicate extreme pain and resistance to treatment, it does not always confirm intractability. A high pain score does not always necessitate an intractable diagnosis. As such, this should not always be used as a determining factor for code assignment.

Considering status migrainosus after a certain period of time

Rarely is status migrainosus assigned based on the duration of symptoms. Status migrainosus may be assigned if multiple attacks of migraine occur closely together, and the attacks are prolonged and unrelenting. In those cases, the health care provider would likely acknowledge that there was not a single prolonged attack of migraine. If this is unclear, additional communication is warranted.

Using a previous code for a different reason

A previously assigned code for a different reason does not mean the code is correct for the current reason. This is especially true if that previous reason was documented by the health care provider and later ruled out. Review the current documentation carefully.

Using each associated symptom for code assignment

Nausea and photophobia are commonly reported symptoms with migraine headaches and should be coded when documented. Code only associated symptoms that are of separate clinical significance.

Assigning a preferred diagnosis to meet policy requirements

The acceptance of a diagnosis by a payer does not always indicate that a diagnosis is allowed or appropriate for that particular situation. If there is a difference of opinion between clinical documentation and a payer’s policy, review the documentation to understand why the payer may not be covering the claim and take the required appeal action.

Claim denials: distinguish the code problem from the service problem

Just because a payer denied a claim, it does not necessarily mean that the diagnosis is incorrect. Look at the payer’s explanation of denial for the answer. The response to an incomplete code is different from the response to a missing authorization and an unsupported procedure.

One example is that a claim for chronic migraine, coded correctly, may still be missing the treatment history required for the code. Replacing G43.E19 with a different code for migraine would not solve the issue with missing treatment history.

Organize your work by cause for denials and rejections. If there are several claims that are all grouped by the same incorrect code mapping in a billing system, correct the code mapping. If the problem is conflicting notes, rather than ask the provider to “document better” or “document more clearly,” give an example of the conflicting notes and ask them to explain it in more detail.

Procedure modifiers and care settings

ICD-10-CM diagnosis codes cannot be modified by CPT/HCPCS procedure modifiers. A modifier is to be applied to the service code to which it applies, if the documentation and the reporting rules support it.

Do not append modifier 25 or 59 to G43.909. Similarly, do not use modifiers automatically if the visit and treatment occur on the same day. Determine appropriateness based on the nature of the service(s) provided, edits, and documentation.

Emergency, office and telehealth visits

In the absence of documentation, a migraine emergency visit cannot necessarily be coded to a level of intractability or status migrainosus, and an office follow-up visit cannot necessarily rule in intractability or status migrainosus. The diagnosis follows the patient, and is not necessarily tied to the location of care.

Telehealth visits do not create a migraine diagnosis family. Select and code the appropriate diagnosis. After that, determine if additional telehealth services are warranted, and code them appropriately. Do not copy and paste procedure/Place of Service (POS) instructions from an old article, without establishing their effective date.

Injections and Infusions, and other diagnoses

When treatment is documented, the record must support what was actually administered. Diagnosis coding is not to be used to determine the appropriate quantity of drug. Separate the services and diagnoses to prevent an error in service coding, disguised as a diagnosis coding change.

When a provider documents an adverse drug reaction (ADR) or associated condition, review the relevant coding and/or sequencing instructions. Headache and epilepsy should not automatically warrant coding of an adverse effect of a drug or epilepsy, respectively, solely because there are neurologic symptoms.

Current ICD-10-CM update: use the correct effective date

CMS and CDC have stated that the FY2027 ICD-10-CM cycle will start on 1 October 2026. The applicable period for CMS and CDC is from 1 October 2026 to 30 September 2027. Officially posted updates may shorten or extend this period, or change the applicable encounter date.

In patient reporting, use the code set that was in effect at the time of discharge. In outpatient reporting, use the code set that was in effect at the time of the encounter. A claim submitted in October for a prior service is not considered to be for the October service, and is not subject to the codes that were released for October.

A blog post may state the year for which ICD-10 codes were revalidated, but that does not necessarily mean that all the codes in the blog have been revalidated. Each year, it’s helpful to review the complete ICD-10 code descriptors to verify code validity, as well as the Index, Tabular Instructions, and any changes that will impact template or payer processing.

G43.E should not be considered a new category for FY2027 just because an article for that year has been posted. New code and code update claims must be made only after an official communication.

Frequently asked questions about migraine ICD 10

What is the ICD-10-CM code for migraine?

Migraine belongs to G43. G43.909 identifies migraine, unspecified, not intractable, without status migrainosus. Use a more specific complete code when supported by the documented migraine type and characteristics.

What is the code for migraine without aura?

G43.009 identifies migraine without aura, not intractable, without status migrainosus. Other G43.0 codes apply when intractability, status migrainosus, or both are documented.

What is the code for migraine with aura?

G43.109 identifies migraine with aura, not intractable, without status migrainosus. Chronic migraine with aura belongs to G43.E, with a complete code selected for the documented characteristics.

Which ICD-10-CM codes identify chronic migraine?

G43.7 identifies chronic migraine without aura, while G43.E identifies chronic migraine with aura. Select a complete code based on the provider’s diagnosis, intractability, and status migrainosus.

Is G43.909 the same as R51.9?

No. G43.909 reports diagnosed migraine with an unspecified type and the other characteristics in its descriptor. R51.9 reports headache, unspecified. Select the code supported by the encounter’s established diagnosis or symptoms.

Can a migraine lasting more than 72 hours be coded as status migrainosus?

Duration is part of the clinical assessment, but it does not let a coder independently diagnose status migrainosus. Use the provider’s documented diagnosis and the applicable ICD-10-CM instructions; clarify an uncertain record.

PUT THE CLINICAL RECORD FIRST

Many providers notate migraine onset as “probable” or “suspected” and leave off other key details like what subtype is present (e.g., basilar, with or without aura, etc.), presence/absence of allodynia, phonophobia, and photophobia. Review the relevant distinctions and check the full code. Then, separately, analyze authorization and service requirements.

If migraine claims are repeatedly corrected, review a few examples of the records and payer responses. A review of the documentation and coding can show whether the problem is due to a code mapping issue, a lack of clear assessment, or lack of service. Once the reason for the persistent issue is identified, this provides the practice with a clear remedy.