Background/Aims With the implementation of ICD 10 CM and ICD 10 PCS less than two years away, there are still unanswered questions as to how research teams will effectively translate or use ICD 10 codes in research. Approximately 84% of the ICD 10 codes have only approximate matches with 10% having multiple matches and only 5% have exact one-to-one matches between ICD 9 and ICD 10. With the number of codes increasing five-fold, this offers additional opportunities and risks when pulling data.

Methods Besides looking at the General Equivalency Mappings and other tools that are used to translate ICD 9 codes to ICD 10 codes, we will examine some common research areas where only approximate matches between ICD 9 and ICD 10 exist. We will also discuss how the finer level of detail that ICD 10 gives allows research teams to pinpoint exactly what type of asthma, Crohn’s disease, and diabetic retinopathy they wish to study without including some of the other cases that do not meet their research criteria.

Results There are significant ambiguities and irregularity in several common areas such as diabetes, mental health, asthma, and gastroenterology due to approximate, multiple, or combination matches. Even in the case of exact matches such as an old myocardial infarction where there is an exact match, the definition of when a myocardial infarction becomes “old” is different.

Conclusions ICD 10 offers a finer level of detail and a higher level of specificity, thereby allowing research teams to be more targeted when pulling data. On the other hand, research teams need to exercise caution when using GEMs and other tools to translate ICD 9 codes into ICD 10 codes and vice versa, especially if they are looking at data that overlaps the implementation date of October 1, 2014.