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Tips to Improve ICD-10-CM Coding Accuracy

Apr 2, 2024 | News

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The Medical Group Management Association suggested a decade ago that clinical staff at physician offices should invest 16 to 24 hours in learning proper ICD-10-CM coding. That was under a simpler system, ICD-9-CM, and prior to today’s focus on value-based care, which includes diagnosis codes in calculations.

How much time have clinicians in your office devoted to ICD-10-CM coding skills? Many providers believe that their solid foundation in pathophysiology eliminates the need for diagnosis coding training. However, ICD-10-CM is full of idiosyncrasies and nuanced rules.

Try these suggestions to improve the accuracy and specificity of your diagnosis coding, which should result in fewer queries, claims denials, or negative audits.

  • Don’t trust your EHR. If your electronic health records offer pull-down menus of codes, do not simply select the code at the top of the list. It will likely be a code for a diagnosis that is “not otherwise specified (NOS)”.  NOS codes should be used when the provider doesn’t know all the information for more specific coding or failed to document it (C50.919 Malignant neoplasm of unspecified site of unspecified female breast). Sometimes, there is a reason this information isn’t known, but usually, it is a function of poor documentation. Be as specific as possible.
  • Know the lingo. “Not elsewhere classified (NEC)” means that a diagnosis does not have a unique code, but instead is lumped in with other diagnoses. The documentation must still list the specifics, for example, documented granulomatous angiitis of the nervous system would be reported with I67.7 Cerebral arteritis, not elsewhere classified.
  • Documented words are the only documentation that counts. CMS does not recognize ICD-10-CM codes as documentation. Conditions must be documented, and then described with clinical impressions, plans for case, severity, and chronicity. For example, your patient was treated today for six axillary skin tags. The diagnosis code for skin tag is L91.8 Other hypertrophic disorders of the skin, but this code is also used to report acquired cutis verticis gyrata and other rare skin conditions.
  • ‘One and done’ isn’t always the case. Many diagnoses require multiple codes. Providers should never report a code describing a condition “in diseases classified elsewhere” as a solidary diagnosis. ICD-10-CM requires a second code describing the etiology, for example, I32 Pericarditis in diseases classified elsewhere could be reported with M05.39 Rheumatoid heart disease with rheumatoid arthritis of multiple sites. Also, codes that capture a pathology based on alcohol consumption are incomplete. For example, K70.30 Alcoholic cirrhosis without ascites should be reported with a code from F10 Alcohol related disorders, to capture the abuse, dependence, or remission so that the status of the alcohol use is captured.
  • Please abstract ‘the rest of the story.” Providers often stick to the chief complaint when abstracting codes following an encounter, when they should document and abstract every diagnosis that affected the care planning for the patient. Mild dementia in a patient who has hemiparesis from a recent stroke may struggle with physical therapy appointments or home exercises, as well as with their home medication regime. Tell the complete story of the patient, as it affects the current chief complaint.
  • What’s important? It’s a lot to remember, but the important message is to document thoroughly, and abstract codes that match the documentation.

What documentation challenges are you facing? 

Written by Sheri Poe Bernard, CRC, CPC, CDEO, CCS-P, Director, Risk Adjustment Assessment and Compliance.  Granite GRC can help navigate your toughest risk adjustment challenges.  Contact us at, or call (717) 556-1090.