Coding For Encounter Following an Accident and Its External Causes

When a person has an accident, such as a fall while sleeping, and there are no injuries, the encounter following an accident and its external causes needs to be reported.

baby falls while sleeping and how to code for an encounter after an accident in which there are no injuries

Have you ever been injured while sleeping?

I asked myself that question.

Sure, yes, I have slept in an awkward position and sometimes the pillow I was using would cause neck pain. And I have slept on my stomach and it put stress on my back. I have also slept on a poor mattress before that has caused some back pain.

Upon further reflection, I recall a time when my son, only about 9 months old at the time, fell off a sofa and hurt himself. Can you imagine the concern if it were your child?

It really scared me, and I worried that he could have broken his nose or suffered a concussion. Thankfully, though, he was fine.

Encounter Following an Accident – Outpatient Coding Scenario

Let’s look at the following documentation:

A 9-month old child rolled off the sofa and onto the floor while sleeping at a relative’s home. The mom stated she was sitting next to her child on the sofa, and while she was looking away, the incident occurred. The mom was very concerned about possible injury and brought the child to the office. The pediatrician examined the child for any outward signs of injury or sustained trauma and found no injuries. The encounter was for observation; suspected injury after fall was ruled out. The mom was instructed to look for any signs that may develop.

First of all, the patient presented to the pediatrician’s office after having an accident (fall), but no symptoms or injuries were diagnosed or documented.

Observation Z Codes – Coding Guidelines

According to ICD-10-CM Official Guidelines for Coding and Reporting, “There are three observation Z code categories. They are for use in very limited circumstances when a person is being observed for a suspected condition that is ruled out. The observation codes are not for use if an injury or illness or any signs or symptoms related to the suspected condition are present. In such cases, the diagnosis/symptom code is used with the corresponding external cause code.”

The observation Z code categories are:

  • Z03  Encounter for medical observation for suspected diseases and conditions ruled out
  • Z04  Encounter for examination and observation for other reasons (Except: Z04.9, Encounter for examination and observation for unspecified reason) 
  • Z05  Encounter for observation and evaluation of newborn for suspected diseases and conditions ruled out

The guidelines further state that “the observation codes are primarily to be used as a principal/first-listed diagnosis. An observation code may be assigned as a secondary diagnosis code when the patient is being observed for a condition that is ruled out and is unrelated to the principal/first-listed diagnosis (e.g., patient presents for treatment following injuries sustained in a motor vehicle accident and is also observed for suspected COVID-19 infection that is subsequently ruled out)…” 

For more information on the ICD-10-CM coding guidelines related to reporting for observation Z codes, see the FY 2021 coding guidelines. They are not posted here due to not being relevant to the current coding scenario. 

In this case, an observation Z code is used for the following reason: The parent thinks the child could have a condition, but with no signs or symptoms and after careful review by the physician, injury is ruled out.

ICD-10-CM Codes – Locate and Verify

Encounter for Observation

In the Alphabetic Index, look under Observation (following) (for) (without need for further medical care), accident NEC Z04.3. This can then be verified in the Tabular List as:

Z04.3, Encounter for examination and observation following other accident

NEC means “Not elsewhere classifiable.” According to the coding guidelines, “This abbreviation in the Alphabetic Index represents “other specified.” When a specific code is not available for a condition, the Alphabetic Index directs the coder to the “other specified” code in the Tabular List. This abbreviation represents “other specified.” 

The note at Z04 indicates that this category is also used for administrative and legal observation status. Be sure to read all the instructional notes before assigning this code.

External Causes

Codes from Chapter 20. External Causes of Morbidity (V00-Y99) should be used to provide additional information as to the cause of the condition based on the provider’s documentation. These codes are secondary codes used to identify the cause, intent, place where the patient was when injured, patient’s status, and activity being performed at the time. These codes are never reported alone.

In this scenario, the child fell from a sofa while visiting a relative’s home, and the activity was sleeping. So we need to find the appropriate codes to tell the story.

In the External Cause of Injuries Index, look under Fall, falling (accidental)/from, off, out of/furniture NEC W08. We can then verify the correct code in the Tabular List as

W08.XXXA, Fall from other furniture, initial encounter

The 7th character “A” indicates that patient is receiving active treatment.

In the External Cause of Injuries Index, look under Place of occurrence/residence (noninstitutionalized) (private)/house, single-family/specified NEC Y92.018. This code can then be verified in the Tabular List as:

Y92.018, Other place in single-family (private) house as the place of occurrence of the external cause

In the External Cause of Injuries Index, look under Activity (involving) (of victim at time of event)/sleeping (sleep) Y93.84. We can then verify this code in the Tabular List as:

Y93.84, Activity, sleeping

Be sure to review all instructional notes before making your final code assignment.


In summary, when a patient presents for a suspicious condition after an accident, and there are no signs and symptoms and no diagnosis, we need to code for the encounter following the accident.

We also need to assign the external cause codes based on the documentation.

And hopefully, you will take my advice and get your child checked out after a fall like this just to be on the safe side.

baby sleeping and ICD-10-CM coding for an encounter following an accident and its external causes

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This post has been updated to reflect the FY 2021 coding guidelines.





  1. My question is if patient presents to er with right ankle pain due to twisting of knee when stepping in hole. X-rays were done an no specific injury was found. The doctor documents diagnosis as right ankle pain.
    Do you code this as right ankle pain with the E-codes or unspecified injury of the right ankle?
    This has been topic of conversation and I cannot find exact info on this example. Thank you for your help.

    1. Hi Kelly,

      I would code for the right ankle pain and then use external cause code(s) to indicate the cause. There is a code for right ankle pain. E codes have been replaced with codes from V00-Y99 in ICD-10-CM.

      The FY2020 coding guidelines state, “Codes that describe symptoms and signs, as opposed to diagnoses, are acceptable for reporting purposes when a related definitive diagnosis has not been established (confirmed) by the provider.”

      Also, there is a note at M00-M25 that states “Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition.”

      I hope this helps.

  2. What if at the follow up visit the patient has a new issue and the doctor gives a new diagnosis for this old condition of pain due to MVA? Is this still coded with a “D” as the 7th character or “S” as this is a subsequent follow up visit?

    1. Per the ICD-10-CM coding guidelines for the use of A, D, and S, “A” is for active treatment of the condition and not whether the patient is being seen the first time; “D” is for when active treatment of the condition has been completed and routine care is provided during healing or recovery phase; “S” is for when complications or conditions arise as a direct result of a condition. Also, “for complication codes, active treatment refers to treatment for the condition described by the code, even though it may be related to an earlier precipitating problem.”

  3. I transitioned over to ED coding and it is very intimidating. I get a lot of auto cases and always stuck when the reason states MVA but then there are symptoms noted. Do I code the symptoms only? I was told to code the Z04.1 but I don’t feel like that is appropriate for reason either

    1. Hi Rosa,

      According to the coding guidelines, category Z04 is to be used when a person without a diagnosis is suspected of having an abnormal condition, without signs or symptoms, which requires study, but after examination and observation, is ruled-out.

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