Primary Care Coding Alert

Know when, and when not, to use these commonly used codes.

You know that Chapter 18 in ICD-10 is the go-to chapter for Symptoms, Signs, and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified. You routinely comb through the chapter when your provider doesn’t provide a definitive diagnosis for a patient’s conditions but notes the patient’s current complaint(s).

But how well do you know the guidelines associated with the signs and symptoms codes, or the codes themselves? Read on, and see if you know them well enough to bust these four common myths.

Myth 1: Codes from Chapter 18 cannot be used as a principal diagnosis.

This myth is pretty easily refuted once you examine ICD-10 guideline I.C.18.a, which tells you that “codes that describe symptoms and signs are acceptable for reporting purposes when a related definitive diagnosis has not been established (confirmed) by the provider.”

In other words, Chapter 18 “captures signs and symptoms that are not captured in other chapters and, as such, may be the only information the provider has at the end of the visit if the symptoms are still under investigation and a definitive diagnosis has not been made,” explains Melanie Witt, RN, CPC, MA, an independent coding expert based in Guadalupita, New Mexico.

Example: A patient reports complaining of abdominal pain, diarrhea, fever, and loss of appetite. Your provider suspects the patient has Crohn’s disease but cannot provide a definitive diagnosis as results of a test for the disease have yet to be obtained. In this case, you would use signs and symptoms such as R10.10 (Upper abdominal pain, unspecified), R19.7 (Diarrhea, unspecified), R50.9 (Fever, unspecified), and R63.0 (Anorexia) — because one of the synonyms for the condition is loss of appetite — as principal diagnoses for this encounter until test results provide a definitive diagnosis.

Myth 2: Codes from Chapter 18 cannot be used along with a definitive diagnosis.

This myth is only partly incorrect, as, “in some cases, you may be able to report a code from Chapter 18 if the sign or symptom is not normally associated with a definitive diagnosis,” says Chelle Johnson, CPMA, CPC, CPCO, CPPM, CEMC, AAPC Fellow, billing/credentialing/ auditing/coding coordinator at County of Stanislaus Health Services Agency in Modesto, California. For example, “you would not report a patient diagnosed with fibromyalgia [M79.7] with an additional diagnosis of other fatigue [R53.83] as that is an expected symptom of fibromyalgia,” Johnson goes on to note.

But, per guideline I.C.18.b, you may report a sign and symptom code in addition to a related definitive diagnosis when the sign or symptom “is not routinely associated with that diagnosis, such as the various signs and symptoms associated with complex syndromes.”

Example: Your provider diagnoses an elderly patient with essential tremor and unsteadiness on her feet. While the two conditions can be connected, the patient’s unsteadiness is not a sign or symptom routinely associated with essential tremor, which mostly affects the hands. So, you would be correct in coding G25.0 (Essential tremor) with R26.81 (Unsteadiness on feet) in this situation, making sure that the primary diagnosis, the essential tremor, is sequenced first.

Pro coding tip: As much as possible, consult a good medical dictionary or use Google to research unfamiliar conditions and learn about their typical symptoms.

Myth 3: Chapter 18 codes should be used when a provider describes a diagnosis as “probable,” “suspected,” “questionable,” “ruled out,” or with some similar language.

This myth probably stems from a misunderstanding of ICD-10 guideline II.H, which states “if the diagnosis documented at the time of discharge is qualified as ‘probable,’ ‘suspected,’ ‘likely,’ ‘questionable,’ ‘possible,’ ‘still to be ruled out,’ ‘compatible with,’ ‘consistent with,’ or other similar terms indicating uncertainty, code the condition as if it existed or was established.” However, the guideline goes on to state that “this guideline is applicable only to inpatient admissions to short-term, acute, long-term care, and psychiatric hospitals.”

Instead, you must look to outpatient guideline IV.H, which states, “Do not code diagnoses documented as “probable”, “suspected,” “questionable,” “rule out,” “compatible with,” “consistent with,” or “working diagnosis,” or other similar terms indicating uncertainty. Rather, code the condition(s) to the highest degree of certainty for that encounter/visit, such as symptoms, signs, abnormal test results, or other reason for the visit.”

But the myth does have a grain of truth. For while your provider may rule out a diagnosis in the note, you might still be able to use a Chapter 18 code as, like the first myth, “even though the provider has ruled out a definitive diagnosis, there will still be findings or symptoms in the note that you can use,” notes Witt.

Myth 4: You can only find codes for signs and symptoms in Chapter 18.

This one is purely myth. “Some of the body system chapters also include symptoms related to that area,” notes Witt. So, it is important not to limit your search for signs and symptoms codes to just one chapter.

Examples: “One code that immediately comes to mind is N63.- [Unspecified lump in breast],” says Johnson. And there are countless others, such as M25.5- (Pain in joint).