ICD coding guidelines are very important for coding diagnosis codes. Now, as we  have started using ICD 10 codes we have to be more accurate while coding diagnosis codes. I know we already have ICD 10 coding guidelines in codebooks but we hardly refer them till it is very essential. There is the lot of difference between ICD9 and ICD10 codes. ICD 10 codes are very specific in all the chapters. I am just going to take few points which are important for medical coder to remember while using these ICD 10 codes. In short I will try to cover few basic coding guidelines which we can help you in clearing CPC exam as well.

Short ICD coding Guidelines for Medical coders

Code the most Specific code

This is very common guideline which we followed in ICD 9 and we will follow in ICD 10 as well. The main point here is to remember not to code any unspecified or other specified code when we have a more specific code present. For example, right lower quadrant abdominal pain has a specific ICD 10 code R10.31 and we have an unspecified abdominal code as well R10.9. The unspecified code cannot be coded with specified code as per ICD 10 coding guidelines. Also we have separate code for right, left, bilateral and unspecified site for extremities in ICD10. So, never use any unspecified site code when they have clearly documented the diagnosis in the left, right or both sides (bilateral) of the extremity. I hope, this is very easy to learn and apply, especially during Medical coding Certification exams.


Use of Primary & Secondary diagnosis codes

Like ICD 9, ICD 10 also has few diagnosis which should always be using as primary diagnosis. This is very important to remember because as per ICD 10 guidelines these cannot be used as secondary diagnosis. In code books as well these codes will be denoted by Pdx which mean they have to be used only as Primary diagnosis(Pdx) only. I have already shared as list Primary diagnosis in my previous post. These will be mainly Z codes which are mostly status codes like V codes in ICD 9. Keep an eye while using Z codes because a claim can be denied if any primary diagnosis is used as secondary diagnosis.

Use of Multiple Diagnosis codes

Multiple diagnosis codes occur only when there are injuries or complication present in the body. For injuries ICD 10, we have separate codes for initial, subsequent or sequela encounters. In ICD 10, one has to be very careful with using these codes and finding out whether the patient is still taking active treatment or not. This is very important topic we still have to learn more about it. For complication in pregnancy we have separate ICD 10 for trimester. In ICD 10 Z codes have replaced the V codes of ICD 9. Z codes are used for specifying the weeks of gestation. These codes belong to Z3A category and should never be using as primary diagnosis. These codes are to be used only with pregnancy complication codes.