In ICD-10 coding, what is true about the first character?

In ICD-10 coding, what is true about the first character?

• A. Will always be numeric
• B. Will always be alphabetic
• C. Will always be alphanumeric
• D. The letter U will be used as the first character

Answer: (B)

The first character in ICD-10 codes is always a letter. This convention designates the broad chapter or category of the condition, providing a clear, distinct starting point for the code that is easy to recognize across the system. After that initial letter, digits (and sometimes additional letters) add specificity to the code, but the very first position cannot be a number. Also, the idea that the first character would be a specific letter like U isn’t correct in ICD-10-CM/ICD-10-PCS, since U is not used as the first character and is reserved for future use. So the correct understanding is that the initial character is a letter.

The first character in ICD-10 codes is always a letter. This convention designates the broad chapter or category of the condition, providing a clear, distinct starting point for the code that is easy to recognize across the system. After that initial letter, digits (and sometimes additional letters) add specificity to the code, but the very first position cannot be a number. Also, the idea that the first character would be a specific letter like U isn’t correct in ICD-10-CM/ICD-10-PCS, since U is not used as the first character and is reserved for future use. So the correct understanding is that the initial character is a letter.