EM Coding Alert

Hint: Side effects may affect MDM leveling.

With medical records constantly on the move between offices as patients require different specialists, it’s imperative that each physician have all the information possible to safely and effectively treat a patient. This includes knowledge of long-term drug therapies. Starting Oct. 1, 2022, with the implementation of ICD-10 2023, primary care coders have a handful of new Z79.- (Long term (current) drug therapy) codes to report to help round out patient records.

Here are all the new codes you might need, along with examples of how they can affect evaluation and management (E/M) medical decision making (MDM).

Refresh Your Z Code Knowledge

The Z codes, as explained in ICD-10-CM Official Guidelines, Section I.B.19.d., “may be assigned as appropriate to further explain the reasons for presenting for healthcare services, including transfers between healthcare facilities, or provide additional information relevant to a patient encounter.” They are essentially used as supporting details.

Code expansion: In 2022, the code set went from Z79.0- (Long term (current) use of anticoagulants and antithrombotics/antiplatelets) straight to Z79.8- (Other long term (current) drug therapy). With the 2023 code set, you can account for the use of immunomodulators, immunosuppressants, and chemotherapeutic agents with the following codes and subcategories:

Z79.6- (Long term (current) use of immunomodulators and immunosuppressants):

• Z79.60 (Long term (current) use of unspecified immunomodulators and immunosuppressants)
• Z79.61 (Long term (current) use of immunomodulator)
• Z79.62- (Long term (current) use of immunosuppressant)
• Z79.63- (Long term (current) use of chemotherapeutic agent)
• Z79.64 (Long term (current) use of myelosuppressive agent)
• Z79.69 (Long term (current) use of other immunomodulators and immunosuppressants)
• Z79.85 (Long-term (current) use of injectable non-insulin antidiabetic drugs)

Note also that Z79.62- and Z79.63- will also break down into more specific drug codes.

Document Everything That Affects MDM

ICD-10 Z79.- codes also play another important role in helping to justify moderate and high MDM levels of an E/M visit. “Prescription drug management” is an example of moderate risk of morbidity from additional diagnostic testing or treatment, while “Drug therapy requiring intensive monitoring for toxicity” is an example of high risk. The Z79.- codes your documentation supports may play a role in determining the complexity of the MDM involved in the patient’s care.

Example 1: Some long-term drug therapies carry their own side effects, which alone could push an encounter to the next highest MDM level. For example, if the patient record shows they recently started immunosuppressant infusions with their GI specialist to treat a major chronic disease such as Crohn’s disease or ulcerative colitis, you could well be able to justify 99214 (Office or other outpatient visit for the evaluation and management of an established patient, which requires a … moderate level of medical decision making …).

Here’s why: Immunosuppressants are known to globally impair the body’s entire immune response, whereas immunomodulators are more selective and target portions of the immune system. They both interfere with the immune system, however, so the risk of infection is greatly increased, potentially affecting the future health of the patient. If that patient presents to their primary care practitioner (PCP) with a positive COVID-19 test, that patient now has an increased risk of serious illness. An encounter that may have otherwise been considered 99213 (Office or other outpatient visit… low level…) could potentially jump to 99214 or 99215 (Office or other outpatient visit… moderate/high level…).

Example 2: Chemotherapy, and the cancer itself, can be enough to bump an E/M service potentially to 99215 (Office or other outpatient visit for the evaluation and management of an established patient … high level …). That’s because drug therapy requiring intensive monitoring for toxicity is an example of the high risk of complications of patient management element of MDM, while the patient’s condition may also rise to the high level of number and complexity of problems addressed element of MDM. So, reporting a code such as one from Z79.63- may support the higher-level E/M.

Note: “Adding a diagnosis from this expanded category provides a better electronic explanation of these tests or treatments,” explains Carol Pohlig, BSN, RN, CPC, ACS, senior coding and education specialist, University of Pennsylvania Department of Medicine, Hospital of the University of Pennsylvania. “When patients require laboratory testing to ensure drug efficacy and safety, the claim reporting is better serviced with the addition of a specific Z79.- code that identifies the therapy the patient is receiving,” she adds.

This means you should be on the lookout for when Medicare adds these codes to the National Coverage Determinations (NCDs) and Local Coverage Determinations (LCDs) lists and articles. “Ordering lab work to monitor patients on these newly represented medications may not be covered if reported with Z79.8- (Other long term (current) drug therapy) or Z79.899 (Other long term (current) drug therapy),” cautions Halee Garner, CPC, CPMA, CCA, certified coder for Digestive Health Partners in Asheville, North Carolina.