The U.S. government finally launched the highly anticipated tenth revision of the ICD codes used to describe diseases in hospitals across the country. While the change will undoubtedly bring more clarity to the specific types of diseases and injuries hospitals treat patients for, many medical professionals are wary of the change.

The insurance landscape for many Americans is about to get significantly more complicated after the government launched newly mandated ICD-10 codes. According to a report from Forbes, the new reporting system may create unnecessary paperwork and impose hefty costs on the American healthcare system.

Many doctors are worried about the complications this change may bring about. The International Classification of Diseases, the tenth edition, will require medical professionals to begin describing conditions using 140,000 specific new codes to describe treatments given on bills and private insurance claims.

Health insurance providers, business and their human resources departments have all been working tirelessly to update patients about the coming changes. According to Aon Hewitt, a company that provides consulting for employee benefits to a number of companies, doctors and hospitals may continue to use outdated codes that are no longer covered under the new provisions, passing along extra bills to patients.

Chris Miles, the senior vice president of Aon Hewitt’s health division, warns of the potential disruptions that could be caused by doctors using older systems to describe treatments for a wide range of ailments. This could cause delays in claims processing, and in some cases patients may be denied services that are rightfully covered, but not properly described under the new code.