Use of Unspecified Codes in ICD-10: What You Need to Know

Now that ICD-10 has been implemented, it’s crucial to monitor your practice closely for the next 30–60 days to ensure coding accuracy and to tweak processes to locate diagnosis codes efficiently, as well as verify that claims are transmitted successfully and reimbursement has not been affected.

While we all are settling into the daily routine of caring for patients and billing the charges, we will encounter codes that are unclear and don’t identify the patient’s condition.

In both ICD-9 and ICD-10, signs/symptoms and unspecified codes are acceptable and may even be necessary. In some cases, there may not be enough information to describe the patient’s condition or no other code is available to use. Although you should report specific diagnosis codes when they are supported by the available documentation and clinical knowledge of the patient’s health condition, in some cases, signs/symptoms or unspecified codes are the best choice to accurately reflect the healthcare encounter.

Depending on the situation, legitimate uses do exist for a less specific or unspecified code. The ultimate question comes down to: “Does the code reflect as accurately and precisely as possible the patient’s condition or the services performed to maintain or improve that condition for that encounter?”


  • M32.9—Systemic Lupus Erythematosus, unspecified
    Systemic lupus erythematosus NOS
    Systemic lupus erythematosus without organ involvement

    • It is appropriate to use the unspecified code M32.9 for lupus, because there is no other code in the category for just lupus without involvement.
  • M32.10—Systemic Lupus Erythematosus, organ or system involvement unspecified
    • Considering the level of information available to the physician, the findings at the time are nonspecific, and the patient may need further work-up. This code would be more appropriate than a code that guesses at the fact that the patient may have a specific organ or system involvement that has not been confirmed.

The use of any other code within this category would be based on the fact that the patient has some organ involvement that is confirmed and documented. Codes M32.11–M32.15 are specific to organ involvement. Additionally, M32.19 (other organ or system involvement in systemic lupus erythematosus) should be used if the patient has involvement in an organ or system not listed in the category, and M32.8 (other forms of systemic lupus erythematosus) refers to the provider not knowing the nature or specifics of the condition.

However, for codes that provide or require specificity for laterality (left, right or unspecified side), every provider should be able to document right vs. left, as well as the anatomical site.

  • M25.46—Effusion, knee
    M25.461—Effusion, right knee
    M25.462—Effusion, left knee

    • The clinician should be able to code the site/side, and in this case, whether it is the left or the right.
  • M25.469—Effusion, unspecified knee
    • There is little justification for the use of this code, because the specific knee/anatomical site should be known to the clinician treating the patient.

We do not know how payers will handle these unspecified codes, but practices need to be prepared to respond as they receive feedback from the payers. An additional complication is that all payers will not handle these codes the same way at the same time. Therefore, it’s important to be acutely aware of the nuances around the appropriate use of unspecified codes.

Leave a Reply

Your email address will not be published. Required fields are marked *