In the ICD structure, what can the first character be?

In the ICD structure, what can the first character be?

• A. An alpha character (letters except U)
• B. A numeric digit
• C. The letter U
• D. A special symbol

Answer: (A)

In ICD coding, codes are designed so the first position is a letter, not a digit or symbol. This alphabetic opening helps place codes into chapters and keeps the coding structure consistent. The letters used as the first character exclude the letter U, which is reserved for future use or special categories, so the valid first character is any alphabetic letter except U. That’s why the best choice is an alpha character (letters except U).

In ICD coding, codes are designed so the first position is a letter, not a digit or symbol. This alphabetic opening helps place codes into chapters and keeps the coding structure consistent. The letters used as the first character exclude the letter U, which is reserved for future use or special categories, so the valid first character is any alphabetic letter except U. That’s why the best choice is an alpha character (letters except U).