GEMs and ICD-10-CM Assignment
The Centers for Medicare & Medicaid Services (CMS) created the General Equivalence Mappings, or GEMs to assist in the conversion of I-9 to I-10 (other organizations have created similar mapping tools). GEMs helps in plugging in an I-9 code to determine a likely match in I-10 (or vice versa). But even Centers for Medicare & Medicaid Services (CMS) admits the General Equivalence Mappings have serious shortcomings.
Of nearly 70,000 diagnosis codes in I-10, approximately 5 percent match I-9 descriptors. In all other cases, ICD-9 and ICD-10 ” differ so widely that the translation offers only a series of compromises and subjective choices. This is because there is no ?mirror image? of one code set in the other,?
As per their calculations:
? There are 445 instances where a single ICD-9 code can map to more than 50 ICD-10 codes.
? There are 210 instances where a single ICD-9 can map to more than 100 ICD-10 codes.
? There are 6,821 instances in the mappings for diseases where a single ICD-10 code can map back to more than one ICD-9 code.
? There is not a one-to-one match between ICD-9-CM and ICD-10, there are instances where there is no plausible translation from a code in one system to any code in the other system? [emphasis in original].CMS confirms.
? The lesson for physicians and other clinicians is clear: GEMs may not be the ultimate solution and will be better to assign ICD-10-CM codes from the record. CMS concurs, recommending, ?In coding individual claims, it will be more efficient to work from the medical record documentation and then select the appropriate code(s),? rather than attempt to translate information from one code set to the other.
? ICD-10 is not a coding problem at all. It is actually a clinical documentation problem.? To succeed going forward, clinicians should concentrate on documenting the concepts necessary to support accurate code assignment directly in I-10 (such as laterality, episode of care, acute vs. chronic, etc.), rather than worry how the ICD-9 codes ?translate? to ICD-10.