Risk Adjustment

4 Common Medical Coding Errors Made with the 2019 CMS-HCC Model

Written By
Tim Buxton
Director of Coding Services

The HCC Risk Adjustment Model released this April by the Centers for Medicare & Medicaid Services (CMS) for payment year 2020 includes important revisions coders should be aware of. In an effort to support coders and plans working within the updated model, we’ve described several examples of coding errors and ways to resolve them. By following these tips, risk adjustment teams can reduce waste, retain revenue that would have otherwise been lost, and ensure accurate documentation leads to proper care being delivered.


Potential Coding Error #1: Pressure Ulcers


Pressure ulcers are wounds that often occur because a patient is immobile or experienced a minor trauma, such as a cut that gets infected. One example is patients with diabetes who are more prone to getting pressure ulcers because their wounds may not heal as well.

Pressure ulcers are ranked between stages one and five, with five being the most severe. Sometimes in clinical documentation, a provider will describe an ulcer but not stage it. In that case, there’s a risk adjustment code for a pressure ulcer of a particular part of the body at an unspecified stage. Ulcers can also be classified as unstageable, which means that the provider can’t determine the stage of an ulcer. This situation may occur if the affected area is wrapped in a bandage and the provider doesn’t want to remove the dressing.

In previous CMS-HCC models, pressure ulcers of all stages, including unspecified stage or unstageable, were coded. However, in the 2020 model, pressure ulcers of stage one or two or an unspecified stage are no longer included. The primary code for pressure ulcers is L89, but additional codes should be utilized for different parts of the body. For example, L89.116 is the code for “pressure-induced deep tissue damage of right upper back,” while L89.506 refers to “pressure-induced deep tissue damage of unspecified ankle.”

The impact that documenting and coding proper ulcer staging has on RAF is substantial. Excluding other conditions, a 65-year old male may receive a risk score of 0.83 for an unstaged ulcer. However, a stage two ulcer carries an increased score of 1.50, while a stage four ulcer increases the RAF to 2.46.

Note that the ICD-10 guidelines state that stages of a pressure ulcer can sometimes be documented by a nurse or other ancillary staff, not just a physician. If a specific stage can’t be found or the ulcer is termed unstageable, it’s no longer an HCC code and doesn’t adjust for risk.


Potential Coding Error #2: Cannabis Dependence with Withdrawal


Two new codes in the 2019 CMS-HCC Model are F12.23 and F12.93. F12.23 refers to cannabis dependence with withdrawal, while F12.93 is unspecified cannabis use with withdrawal. Previously, the model didn’t include codes for withdrawal from cannabis. Because many types of cannabis use are not documented by amount ingested or level of severity, many such codes are not part of the HCC model.

However, with the newer model, coders should look for documentation that highlights symptoms of withdrawal from cannabis. According to American Addiction Centers, these symptoms include:

  • Feelings of anger, irritability, and/or aggressiveness
  • Sensations of extreme nervousness or anxiety
  • Disturbances with sleep that can include insomnia
  • A decrease in appetite that may or may not be associated with a significant loss of weight
  • Feelings of restlessness and general malaise
  • The onset of feelings of depression

If these symptoms are found in the documentation, the fact that it is withdrawal classifies the condition as an HCC. F12.23 and F12.93 are both in HCC 55 – one addresses substance abuse leading to a serious psychotic problem, and the other addresses substance abuse due to serious psychotic problems.

These codes carry a RAF score for standard Community, Nondual, Aged patients of 0.329, or 0.538 for full-benefit eligible Medicaid patients. Since this code is a new addition to the CMS-HCC model, it’s important for coders to look for evidence of cannabis dependency in order to maximize patient care and revenue.


Potential Coding Error #3: Muscular Dystrophy


The codes for muscular dystrophy, which is a risk-adjusted condition, have been revised and expanded for 2019. Before, there was only one code for this disease – G71.0. Now, it has been extended into four codes: G71.00, G71.01, G71.02, and G71.09. Muscular dystrophy refers to a group of diseases – as diagnostic techniques become more specialized, several muscular dystrophy codes are necessary to capture the range of diagnoses relating to the disease.

G71.00 refers to muscular dystrophy unspecified, G71.01 is Duchenne syndrome or Becker muscular dystrophy, G71.02 correlates with Facioscapulohumeral muscular dystrophy and G71.09 is for other specified types of the disease. Note that coders who utilized G71.0 in the past now need to put an extra “0” on the end to make it a legitimate, acceptable code. If the appropriate muscular dystrophy code is not captured, plans may be missing out on a RAF amount of 0.518 for standard patients and 0.621 for disabled patients.


Potential Coding Error #4: Sepsis as an Infection Following a Procedure


The code T84.4 previously referred to as an infection following a procedure, giving few specifics. Though “T” codes are usually used to document complications and injuries resulting from or after medical care, they were broken down further in 2019 to more specifically describe localized infections.

The new code in the 2019 CMS-HCC model, T81.44XA, represents sepsis as an infection following a procedure. Typically, this code is going to be used for a patient whose operative site became infected in the hospital and spread into their blood. It’s not a code that would be seen in documentation from a physician’s office, only hospital records.

As an example to better illustrate the code, consider a note in a patient file with the message “Examined patient, here’s how he looked today. He had X surgery done two days ago. The operative site became infected, and the patient is now septic. Prescribing X antibiotics.” In this case, a coder has to make the connection that a procedure was performed, that the patient subsequently became septic, and apply the new codes for post-procedural sepsis.

It’s very easy for a coder to simply write “post-procedural status of X surgery two days ago” and code sepsis as an active condition. That’s not improper coding. However, in order to accurately reflect a patient’s medical condition and potentially improve care, the T81.44XA code should be used. Proper utilization of the code triggers HCC 2 and yields a RAF value of 0.352 for standard patients or 0.453 for certain disabled patients.

Awareness, identification, and correction of common medical coding errors can help plans regain revenue that may have otherwise been lost, as well as provide a higher level of care to patients. The RAF value differences highlighted above illustrate the financial benefit that in-depth risk adjustment reviews, knowledge of coding errors, and accurate coding can have for your organization.


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