Home Health ICD-9/ICD-10 Alert

Play by the rules to win the coding game.

Think of coding conventions as clues to help you code accurately. Ignore these rules, and you'll likely fumble your way to denied claims.

It may seem like diagnosis coding involves one rule after another, but that's because accurate coding serves many purposes, experts agree. Following the rules will help your agency remain solvent.

The coding system translates medical terminology into numbers (codes). Originally developed as a way to accumulate statistics on diseases and injuries, ICD-9 codes are now important to home health agencies primarily for reimbursement and claims processing.

In the home health arena, the Centers for Medicare & Medicaid Services assigns case mix values to some of these codes. So the more accurate your coding, the more likely you'll receive the reimbursement you deserve, says consultant Pat Sevast with American Express Tax & Business Services in Timonium, MD.

What you need to know: Besides figuring out the patient's primary and secondary diagnoses, home health coders need to understand what to do with this information. Like a foreign language, coding guidelines use abbreviations, signs, punctuation and format to add meaning.

Because you can't code correctly without understanding coding guidelines, Eli asked the experts to explain some of the most important conventions for home health coders.

Paying attention to coding conventions - cross-references, abbreviations, modifiers, notes and symbols - is crucial for correct coding, says Sue Prophet-Bowman with the Chicago-based American Health Information Management Association.

1. Cross-references direct you to another place in the coding manual. You will find them only in the Alphabetic Index, and following these instructions is mandatory, Prophet-Bowman says. "See" tells you to look elsewhere for a code. "See also" directs you to look under a different main term. "See category" instructs you to review the whole category before assigning the code.

2. Notes help you by providing further instructions. A note may include definitions, suggest possibilities for additional digits or clarify terms. "Excludes" tells you to look for the code elsewhere, explains Department of Veterans Affairs coding expert JoAnn Baker. "Includes" further defines and provides examples (see Eli's Home Health ICD-9 Alert, September 2004, p. 28).

3. Abbreviations include the essential NEC and NOS. NEC means a diagnosis is not elsewhere classified. That is, the coding manual doesn't have a specific code to describe the patient's diagnosis. NOS - not otherwise specified - is used when the record doesn't include enough information to assign a more specific diagnosis code, Baker explains.

4. Modifiers are terms in the diagnosis other than the main terms. For example, if you're looking up "Dermatitis," the terms "allergic" or "contact" are the modifiers for the main term of dermatitis. You'll find modifiers in the Alphabetic Index following the main term. A non-essential modifier doesn't affect the code selection. You should use an essential modifier only if the physician specifies it in the diagnosis.

5. Symbols provide much additional information.  A colon (:) is used after an incomplete term to tell you the code needs one or more modifiers before you can assign it. Parentheses ( ) denote a non-essential modifier (whether it is there or not doesn't affect the code). Square brackets [ ] enclose alternate wording, synonyms or explanatory phrases. Braces { } tell you the statement to the right of the braces modifies the terms enclosed within the braces.