Over 70,000 codes in the ICD-10-CM coding system can easily overwhelm healthcare providers. They find it challenging to follow the guidelines and use these diagnosis codes accurately. Believe us, we understand the struggle.
That’s why our coding experts curated a comprehensive blog explaining the ICD-10-CM guidelines in easy-to-understand words. So, if you are a healthcare provider handling the medical coding part on your own and want to mitigate the errors while coding the encounters, read this guide till the end.
What is ICD-10-CM?
It stands for the International Classification of Diseases, Tenth Revision, Clinical Modification. It is a standardized coding system that healthcare providers or their billing teams use to code the diagnoses of medical conditions and diseases.
The World Health Organization (WHO) reserves the rights for ICD-10-CM. However, to clinically modify the coding system for use in the USA, WHO passed on the authority to the CDC’s National Center for Health Statistics (NCHS). Moreover, all clinical modifications must align with the WHO’s established ICD structure and conventions.
ICD-10-CM Coding Guidelines
The Centers for Medicare and Medicaid Services (CMS) and NCHS provide detailed guidelines for the proper use and assignment of the ICD-10-CM codes when reporting patient encounters and diagnoses. Here are some guidelines that ensure error-free code reporting.
Locating a Code
When selecting a code in the ICD-10-CM that accurately corresponds to the reason for the visit or diagnosis in the patient’s medical record, locate the term in the alphabetic index and then verify the code in the tabular list. Also, keep a keen eye on the instructional notations appearing in the tabular list and alphabetic index.
Checking both list and index is crucial because the alphabetic index may not reveal the full code. Thus, you should check the tabular list for any applicable 7th character and laterality.
You may find a dash (-) at the end of an entry in the alphanumeric index, indicating that it requires additional characters. However, even if a dash (-) is missing, you must refer to the tabular list to verify that the 7th character is needed.
Code Detailing
The ICD-10-CM guidelines emphasize code detailing. That is, you must always strive to use diagnosis codes at their highest number of characters available and align them to the highest level of specificity documented in the patient’s medical record.
For the unversed, the ICD-10-CM codes’ characters can vary from a minimum of 3 to a maximum of 7 characters. A three-character code is often included as a category heading, which may be further segregated into subcategories with the use of 4th/5th/6th characters. The more the characters, the greater detail it provides.
You can only use a three-character code if further subcategorization is not available. Besides, the ICD-10-CM code will be considered invalid if you fail to report the full characters required for that specific code, including the 7th character.
Multiple Codes for a Single Condition
In addition to the etiology/manifestation, some single conditions require you to report more than one ICD-10-CM code to completely define the condition affecting multiple body systems.
Etiology refers to the cause, and manifestation is the effect. For instance, if a virus causes a rash, you will use the virus code to report the etiology and the rash code to detail the manifestation.
Besides, under the tabular list, you may find “use additional code” notes that are not part of an etiology/manifestation pair and require a secondary code for defining a condition properly.
The sequencing rule for these ICD-10-CM codes is the same as the etiology/manifestation pair. That is, if there is a note “use additional code” then you should add a secondary code if known. For instance, if a patient has pneumonia caused by a specific bacteria, you would use the code for pneumonia and an additional code to report the bacteria.
Combination Code
You should only assign the ICD-10-CM combination code when the alphabetic index directs you to use it or when it completely identifies the diagnostic conditions.
A combination code is a single code that classifies a diagnosis with associated complications, a diagnosis with an associated manifestation, or two diagnoses. You can identify these codes by reviewing the exclusion/inclusion notes in the tabular list and referring to subterm entries in the alphabetic index.
If the combination codes lack the specificity required to define a complication or manifestation, you can use an additional code as a secondary code.
Sequela (Late Effects)
According to the ICD-10-CM guidelines, you should report sequela with two codes in sequence. The nature or condition of the sequela comes first, and the sequela code follows. An exception is allowed where the sequela code is followed by a manifestation code identified in the tabular list or the code for sequela has been expanded at the 4th, 5th, or 6th character levels to include one or more manifestations.
A sequela can be defined as the residual effect once an injury terminates or after the disease’s acute phase. Besides, no time limit is associated with it, as it may occur early or after several months or years, as in the case of infertility due to tubal occlusion from old tuberculosis, scar formation from a burn, etc.
Impending or Threatened Condition
When a patient’s medical record defines a condition as ‘threatened’ or ‘impending’ at the time of discharge, follow these ICD-10-CM guidelines:
- If the condition develops, code it as a confirmed diagnosis.
- If the condition did not occur, you should look for terms like ‘threatened’ or ‘impending’ in the alphabetic index.
- If there are specific codes available for ‘threatened’ or ‘impending’ conditions, you should always use these codes.
- If specific codes are unavailable, you should code the underlying condition that may have led to the ‘threatened’ or ‘impending’ state.
Use of Sign/Symptom/Unspecified Codes
Yes, the ICD-10-CM guidelines emphasize using the specific diagnosis codes supported by comprehensive documentation and clinical records. However, quite often, a specific code fails to explain the patient’s symptoms or conditions precisely.
In such situations, signs/symptoms or unspecified codes must be used to report the encounter accurately. Here are some scenarios where the use of these codes is not only acceptable but also necessary:
- If the patient presents with symptoms but the cause is unknown, you should report symptom codes, such as abdominal pain, fever, cough, etc.
- If the diagnosis is suspected but not confirmed, use an unspecified code, such as unspecified back pain, unspecified pneumonia, etc.
- If tests are pending, use signs/symptoms or unspecified codes reflecting the current knowledge. For example, if a patient has a fever and a rash, but test results are pending, use codes for fever and rash.
- If the patient declines recommended tests, document the reason for refusal and assign the code based on the available information.
- It may be appropriate to use a symptom code if the patient’s condition is stable and does not require immediate or further investigation.
Other ICD-10-CM Guidelines
The guidelines we discussed above are important to follow. However, it does not mean that you can ignore the rest of the rules. Thus, here’s a quick list of all the other guidelines you should consider while using the ICD-10-CM coding system:
- Code ranges from U00-U85, Z00-Z99.8, and A00.0-T88.9 are available to help you identify and report complaints, conditions, symptoms, diagnoses, or other reasons for the encounter.
- Use codes R00.0-R99 to define the symptoms and signs when a definitive diagnosis is not established.
- You should not assign signs and symptoms as additional codes if they are associated routinely with a disease process unless otherwise specified.
- Code additional signs and symptoms when they are not routinely associated with a disease process.
- If the same condition is defined as chronic and acute, and the alphabetic index contains separate subentries at the same indentation level, you should code both and sequence the acute code before the chronic code.
- You can use each unique ICD-10-CM code only once for a single encounter. The same applies to bilateral conditions when distinct codes are unavailable to determine the laterality or two separate conditions share the same code.
- ICD-10-CM codes that define the laterality of a condition, i.e., right, left, or bilateral, are available. If the classification does not contain a bilateral code and the condition is bilateral, you may assign separate codes for both sides. However, if the side is unidentified in the patient’s medical records, report the code for the unspecified side.
- ICD-10-CM codes are typically assigned as per the healthcare provider’s documentation. However, there are a few exceptions where clinicians who are not the patient’s healthcare provider are allowed to assign codes based on their medical documentation. Some examples of these exceptions include blood alcohol level, body mass index (BMI), coma scale, pressure ulcer stage, etc.
- You should follow the alphabetic index to code syndromes. However, if the index does not contain the specific syndrome’s details, you may report the code based on the documented syndrome manifestation.
- If a physician documents a ‘borderline’ diagnosis in medical records at the time of discharge, code the diagnosis as confirmed unless there is a specific code for the borderline diagnosis, such as borderline diabetes.
How MediBillMD Helps You Achieve Coding Accuracy & Specificity?
Following a long list of guidelines can seem nerve-wracking, especially when you are handling clinical and administrative duties in-house without hiring professional coders. Plus, we understand that setting up an in-house medical coding and billing department is not cost-effective as it significantly adds to the overhead costs.
However, if you outsource medical coding services to MediBillMD, things can take a positive turn! How? We house a team of certified professional coders (CPCs) who are well-versed in the leading coding systems, such as the ICD-10-CM, and its usage guidelines. As a result, you experience coding accuracy and precision, saving you from auditing risks, financial penalties, and lawsuits.
