A General Equivalence Mapping (GEM) system offers the best industry-wide standard currently available for the forward and backward mapping of ICD – 10 Codes. GEMs can be practically applied as long as clinicians remain aware of their limitations, use them as a starting point, and receive ICD-10 training and education.

A GEM contains an alphabetical index to entries, classification system for procedures, and the appropriate code numbers. The major difference is that GEMs provide clinicians with the ability to forward map from ICD-9 to ICD-10 codes, and backward map from ICD-10 to ICD-9 coding.

An alphabetical list provides the starting point to begin a search for the appropriate code. Just as the words in a language translation guide can contain multiple meanings, the same is true of a GEM. When the index is accessed, it will return as many related items as possible. It’s up to the clinician to narrow the parameters and choose the appropriate code meaning.

A GEM will return a source code for ICD-10 and ICD-9, along with “flags” that are divided into different categories. Flag identify if the system has identified an approximate, combination or no mapping equivalent. A scenario and choice list are also available to provide more information for combination possibilities and the choice list provides alternatives for a combination entry.

Many terms, procedures and concepts have been changed or included in other categories. Adjunct codes are included to provide additional information about a specific procedure and clinicians may be faced with a combination of codes that must be used to identify a specific procedure.

The GEM results will vary depending upon the entity that created it. Additional options are available to help clinicians narrow the data for further specificity, along with instructional notes to help clarify a patient’s particular situation.  GEM mapping between ICD – 10 sets isn’t a mirror copy and there will be discrepancies.

Numerous GEMs exist from multiple sources and clinicians would do well to examine the GEM from their preferred source to ascertain which would be more beneficial and the most applicable within their practice. GEMs return a variety of potentially applicable results for each situation and some are more helpful than others in a particular practice environment.

The number of new codes, greater specificity and multiple options makes the documentation process much more involved, time-consuming and frustrating for clinicians. Searches will result in multiple options that must be examined in-depth to create a match that accurately represents the illness or injury, the type of encounter and the specifics related to an individual patient.

Coders and billers will be using coding books and software systems to make their conversions and many have argued that it may be easier, quicker and more convenient for clinicians to do the same. A GEM can literally return thousands of results for a single conversion query. GEMS are meant to be a short-term solution until clinicians become fluent with the ICD – 10 coding system or design their own crosswalk system.

Utilizing a GEM system will help clinicians ease into the ICD-10 transition, but they should be aware that it isn’t a magic wand or a one-size-fits-all solution. It offers possibilities, potential and helps bridge the gap in coding, but isn’t a definitive solution.

The ability to backward and forward code is the primary attribute and advantage of a GEM system. They’re essentially reference guides that can help clinicians during the ICD-10 transitional period, but should be combined with the clinician’s expert judgment.