Combination Codes Provide Greater Detail for Complicated Conditions

by  Aimee L. Wilcox, CPMA, CCS-P, CST, MA, MT
Jun 13th, 2023

When ICD-10-CM was initially implemented, it was like watching the Discovery Channel where new codes and guidelines seemed to appear that we had never seen before along with new guidelines for how to report them. It seemed like conditions we had never heard of were now before our eyes and suddenly, those diseases were also before us in medical records. The "unspecified" quickly became better specified and there were codes available to describe it. ICD-10-CM contains many combination codes, which the ICD-10-CM Official Guidelines for Coding and Reporting, describe as follows: 

"A combination code is a single code used to classify:

• Two diagnoses, or
• A diagnosis with an associated secondary process (manifestation)
• A diagnosis with an associated complication

Combination codes are identified by referring to subterm entries in the Alphabetic Index and by reading the inclusion and exclusion notes in the Tabular List."

Find-A-Code offers their subscribers access to the American Hospital Association's Coding Clinic, a well-known source of ICD-10-CM guidance used by medical coding and Health Information Management (HIM) professionals throughout the industry. They publish an update quarterly that contains details and instructions that provide clarity in coding. Access to resources like this is like having a personal coding expert in your corner while you work.

ICD-10-CM Provides Instruction for Chapter-Specific Combination Code Reporting

Rather than assigning multiple diagnostic codes, we are instructed to use a single, combination code to accurately represent the patient's condition, if it is available. The guidelines specifically address how to properly report combination codes for multiple conditions listed in each chapter, such as: 

• Combination codes for MRSA infection
• Diabetes mellitus
• Hypertensive heart and chronic kidney disease
• Atherosclerotic coronary artery disease and angina
• Combination codes that include symptoms
• Adverse effects, poisoning, underdosing and toxic effects
• Combination external cause codes

Combination Codes Create Value

Hierarchical condition category (HCC) coding is a risk-adjustment model used to estimate the future health care costs of individual patients by identifying a health risk score. Each ICD-10-CM code is assigned a specific HCC value, which when added together provides a greater picture of that patient's health risk overall. When combination codes are reported properly, it paints a clearer picture of a patient's overall health risk but when the individual diagnoses that make up the combination code are broken out and reported individually, it falsely increases the patient's risk score and increases the estimated costs, resulting in overpayment to payers who manage HCC risk adjusted plans.

Not All Providers are Aware of Combination Code Options

Even though it has been several years since implementation of ICD-10-CM, many providers have not had the time to dig into the guidelines or review the 70,000+ individual codes to see what is in there, and therefore we will often find the individual codes reported separately. As coders, we must put the pieces together to ensure proper reporting of the combination codes where applicable, using the guidelines to direct us.

To assist with this process, guidance through the ICD-10-CM coding guidelines provides this guidance, specific to assigning combination codes: 

"Assign only the combination code when that code fully identifies the diagnostic conditions involved or when the Alphabetic Index so directs. Multiple coding should not be used when the classification provides a combination code that clearly identifies all of the elements documented in the diagnosis. When the combination code lacks necessary specificity in describing the manifestation or complication, an additional code should be used as a secondary code."

Identifying Combination Codes Takes Practice

It is important to apply the individual combination code guidelines to the type of medicine we work in. For example, one of the guidelines often seen in  imaging, pain management, and radiology is,

"Combination codes that include symptoms

ICD-10-CM contains a number of combination codes that identify both the definitive diagnosis and common symptoms of that diagnosis. When using one of these combination codes, an additional code should not be assigned for the symptom."

This seems fairly straightforward; however, we also need to be certain we are not confusing another condition with a symptom and as such, failing to report the combination code when available. For example, radiculopathy is a condition with all of its own symptoms (e.g., pain, extremity weakness, numbness, tingling). These symptoms often develop in the presence of a compressed spinal nerve root, most often related to intervertebal disc herniation, degenerative changes of the spine (spondylosis), malformed structures, or even traumatic injury. Although radiculopathy is a condition and not a symptom, it is often documented as a possible indication of an underlying root cause of a spinal disorder. Providers often report radiculopathy as if it was a symptom when they order additional testing, such as MRI, CT, or other imaging services or even nerve conduction testing.

When radiculopathy is reported as an indication for testing and the results reveal no abnormalities, the code for the radiculopathy would be reported instead of the symptoms of radiculopathy. If the report, however, identified a disorder that supports the patient's radiculopathy, and a combination code exists to report both the underlying condition and the radiculopathy, the combination code should be reported.

To understand this simple application, please review the following x-ray report example.

Exam: X-ray, cervical spine, 4-5 views

History: Radiculopathy

Technique: AP, bilateral obliques and lateral views

Comparison: None

Findings: 

Alignment: Alignment is normal. No evidence of spondylolisthesis.

Vertebral bodies: Normal in height with no evidence of fracture.

Disc Spaces: Well-maintained disc spacing. Mild anterior endplate spurring at C5-C6. Neuroforamina are patent bilaterally. 

Soft Tissues: No soft tissue abnormality is appreciated.

IMPRESSION:

1. Mild degenerative disc disease at C5-6.

2. No other osseous process

Begin your search in the Alphabetic Index under the key word “degeneration” followed by the subterms “intervertebral disc NOS” and finally “cervical.” At this point there should be an option to either “see Disorder, disc, cervical, degeneration” or “with”. When you select “with” it will provide additional options, including: 

Degeneration, degenerative

 Intervertebral disc NOS

  Cervical cervicothoracic

   with

      Myelopathy

      Neuritis, radiculitis, or radiculopathy

At this point, our options are to select either myelopathy or neuritis, radiculitis, or radiculopathy. Reviewing the documentation we see that there is a section noted as HISTORY, which identifies the patient has a history of “radiculopathy.” According to the ICD-10-CM coding guidelines, noted above, this kind of documentation when paired with the option of “with” in the Alphabetic Index, allows a combination code to be reported to explain both conditions, which in this case would be 

M50.122 Cervical disc disorder at C5-C6 level with radiculopathy.

A great way to review for possible combination codes is to review the documentation and compare to the language "with" in the Alphabetic Index to see if there are multiple linked conditions in the documentation that can be reported with a combination code. As always, take the time to review the coding guidelines at least annually. There are so many great insights to the type of coding we do on a daily basis that will help us sharpen our skills and help our providers and fellow coders perform well. 

About Aimee L. Wilcox, CPMA, CCS-P, CST, MA, MT

Aimee L. Wilcox is a medical coding, billing, and auditing consultant, author, and educator with more than 30 years of clinical and administrative experience in healthcare, coding, billing, and auditing. Medicine, including coding and billing, is a constantly changing field full of challenges and learning and she loves both. Aimee believes there are talented medical professionals who, with proper training and excellent information, can continue to practice the art of healing while feeling secure in their billing and reimbursement for such care.