ICD-10-CM Coding Terms and Modifiers

Overview

This lecture introduces the concepts of main terms and subterms in ICD-10-CM coding conventions, explains their differences, and discusses essential versus non-essential modifiers.

Main Terms in ICD-10-CM Coding

• Main terms are nouns naming the diagnosis or reason for a medical encounter.
• Main terms are abstracted from provider documentation during record review.
• The main term should align with the condition or diagnosis for accurate code selection.
• Examples of main terms: appendicitis, disorder, neuropathy, hernia, degeneration.

Subterms and Their Function

• Subterms are adjectives that further describe the main term (noun).
• Subterms are indented under main terms in the codebook, indicating their relationship.
• Subterms specify variations such as type, site, or specificity of the main term.
• There may be multiple subterms, and even subterms beneath other subterms.
• Example: Under the main term "mass," subterms include sites like breast, abdominal, or kidney.

Navigating the Codebook

• Main terms are bolded (or in color) and capitalized in ICD-10-CM indexes.
• Publishers often add lines or columns to help coders track subterms.
• Using a ruler or straight edge can assist in following subterm indentations accurately.

Essential vs. Non-Essential Modifiers

• Essential modifiers (subterms) affect the final code selection.
• Location or descriptive words under subterms can change the code assigned.
• Non-essential modifiers appear in parentheses next to terms and do not affect code selection.
• Examples of non-essential modifiers: "acute," "double," "purulent" (e.g., pneumonia).
• Essential modifiers, such as "allergic" or "aspiration" in "pneumonia," change the code.

Default Codes

• Default codes represent the unspecified version of a condition and are listed next to the main term.
• If only the main term is documented (e.g., "pneumonia" with no specifics), the default code is used.

Exercise Examples

• For "acute appendicitis," main term is "appendicitis" (not "acute").
• "Bipolar disorder" — main term: "disorder."
• "Diabetic neuropathy" — main term: "neuropathy."
• "Inguinal hernia" — main term: "hernia."
• "Intervertebral disc degeneration" — main term: "degeneration."

Key Terms & Definitions

• Main Term — a noun naming the diagnosis, condition, or reason for a medical encounter.
• Subterm — an adjective providing more detail about the main term.
• Essential Modifier — subterm that changes the code selection.
• Non-Essential Modifier — word in parentheses giving extra info but not affecting code selection.
• Default Code — code representing the unspecified form of a condition.

Action Items / Next Steps

• Practice identifying main terms and subterms in diagnosis examples.
• Review the main term and subterm structure in your ICD-10-CM codebook.
• Watch part two of the lecture series.