Is Use of GEMs to Prepare for ICD-10 Wise?

In preparation for ICD-10, the federal government developed GEMs, a translation tool to aid in converting data from ICD-9 to 10, and vice versa. But leaders of outsourced coding, auditing and consulting services firm HRS say the tool has limitations and its use should be carefully considered.

The Centers for Medicare and Medicaid Services and Centers for Disease Control, with input from the American Hospital Association and American Health Information Management Association, created GEMs, which is short for General Equivalence Mappings. The agencies, in guidance available here, explain that GEMs are crosswalks “as they provide important information linking codes of one system with codes in the other system. The GEMs are a comprehensive translation dictionary that can be used to accurately and effectively translate any ICD-9-CM-based data.”

This includes data for tracking quality, recording morbidity/mortality, calculating reimbursement, and converting any ICD-9-CM-based application to ICD-10-CM/PCS such as payment systems, payment and coverage edits, risk adjustment logic, quality measures, and research applications involving trend data, according to the guidance.

“Mapping from ICD-10-CM and ICD-10-PCS codes back to ICD-9-CM codes is known as backward mapping,” the guidance continues. “Mapping from ICD-9-CM codes to ICD-10-CM and ICD-10-PCS codes is known as forward mapping. The GEMs are complete in their description of all the mapping possibilities as well as when there are new concepts in ICD-10 that are not found in ICD-9-CM. All ICD-9-CM codes and all ICD-10-CM/PCS codes are included in the collective GEMs.”

That’s not how Wendy Coplan-Gould, president at HRS, views the comprehensiveness of GEMs, which she calls more of a concept, while codes are specific. If an insurer is reimbursing a provider based on a general code and the provider submitted a specific code, “there is going to be a lot of activity post-reimbursement to fight payments,” she predicts.

That’s because GEMs in many cases are unable to assign specificity so will translate to a generic code, explains Barbara Hinkle-Azzara, vice president of HIM operations at HRS. ICD-10 coding is so specific that payers could drill down and ask providers for more information before paying claims, or payers could decide to pay for specific services using a handful of applicable ICD-10 codes. That means that providers who submit claims with the most appropriate ICD-10 codes might get reimbursed based not on the selected codes, but on another set of codes the payer selected, which likely would affect reimbursement.

While many insurers--particularly Medicaids and Blues--are going directly to ICD-10 for adjudication, a sizable but unknown number of payers will accept ICD-10 codes but revert back to ICD-9 for adjudication. Hinkle-Azzara advises providers to test with several of their major payers to understand how they will adjudicate--and ask when reaching out to test if the payer expects to reimburse based on translating back to ICD-9. Even if a payer refuses to test, ask if they have the ICD-10 code set in their adjudication system or are mapping back to ICD-9, she adds.

Many providers have completed or are developing clinical documentation improvement programs to take full advantage of the specificity of ICD-10 code sets to get optimal appropriate reimbursement and improve the accuracy and usefulness of data for analysis. But GEMs may automatically assign a code that is not as specific as what a provider could be selecting. For instance, the appropriate ICD-10 code may be for “chronic or persistent atrial fibrillation,” but if coding assignment is done based only on GEMs, the code that is mapped is “unspecified atrial fibrillation,” says Hinkle-Azzara.

HRS recommends that providers use native coding practices to assign the most appropriate ICD-10 codes to ensure that the coding reflects what is documented in the medical record. Assigning the codes based on documentation rather than the GEMs will better support accurate reimbursement predictions. But it isn’t just reimbursement expectations that can be affected if providers are not natively assigning the specific ICD-10 codes, Wendy Copland-Gould says. If codes are missing or are non-specific as a result of using the GEMs, data collected and analyzed for severity of illness and risk of mortality, among other indicators, could be negatively affected as well. That could lead an organization to have inaccurate information about the impact of their transition to ICD-10.

Regardless of whether an organization uses GEMs or chooses to natively code to collect data for their initial ICD-10 analysis, it is imperative that they begin or continue to perform dual coding at some point in advance of the ICD-10 compliance date, Hinkle-Azzara counsels. “Dual coding, defined as the application of both ICD-9 and ICD-10 code sets to a patient’s health record, using the coding conventions and coding guidelines that are specific to each code set, is resource-intensive,” she acknowledges. But it is absolutely necessary to enable providers to be prepared to truly know where they stand in regards to appropriate reimbursement and data reporting when ICD-10 becomes a reality.


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