ICD-10 Spotlight: US One of the Last Nations to Transition to New Code Set

The United States is one of the last economically developed nations to transition from ICD-9 to the International Classification of Diseases, 10th Edition, also known as ICD-10. The transition is no small task. On Oct. 1, 2013, our country will begin using the most comprehensive coding system in the world, a set featuring approximately 150,000 diagnosis and procedure codes. More than 100 other countries, including Germany, Canada, Australia and New Zealand already have implemented customized versions of ICD-10 tailored to their single-payer health systems. By the time our implementation mandate arrives, almost 20 years will have passed since the first of our international neighbors transitioned to the ICD-10 code set.

The single greatest challenge physicians will have with ICD-10 is the need for improved documentation. ICD-10 will require physicians to spend additional time and effort documenting to ensure that coders have the appropriate information to complete claims.  While the transition will not be easy for physicians, it is important to remember that the rules governing documentation are not changing. Ask any physician/coder team that has been audited and they will tell you that the documentation guidelines in ICD-9 are very specific, but the codes do not keep up with the documentation requirements due to the fact that the ICD-9 codes do not offer the granularity necessary to adequately reflect the guidelines. With ICD-10, for the first time we will have a clinical classification system that is sophisticated and granular enough to keep up with the regulations. Let’s take a moment to explore both ICD-10 coding systems.

Coding ICD-10-CM

ICD-10-CM, the diagnostic subset, has some additions and changes – the most obvious being the design of the code. Diagnosis codes in ICD-10 have up to seven alphanumeric characters, compared to the five-character system used today in ICD-9. Physicians should expect the learning curve for ICD-10-CM to be much smoother than that of the ICD-10-PCS procedural counterpart. The rules, conventions and guidelines in ICD-10-CM are very similar to what currently appears in ICD-9-CM, with only a few changes.

Let’s use chronic kidney disease (CKD) as an example. Currently, coders are required to make code selections for this disease based on severity, a concept that does not change in ICD-10. Classification of CKD in ICD-10 continues to be based on severity represented by stages I-V, and the disease is assigned from the N18 section of the ICD-10-CM system. End-stage renal disease (ESRD) still only is assigned when it is actually documented, and it is also assigned from the N18 section. For cases in which patients have CKD in conjunction with other diseases, such as diabetes mellitus or hypertension, the ICD-10 book still directs the coder in the proper sequencing of the codes. Furthermore, there are still codes to represent complications of transplants, but in this area there is greater specificity available to represent complications adequately. A newer concept in ICD-10-CM is the multitude of combination codes available. What took us two or three codes under ICD-9-CM now only may take one combination code in ICD-10-CM. Take a look at this example:

  • A patient diagnosed with malignant hypertension and stage V chronic renal disease is admitted to the critical care unit. The patient is now in acute renal failure with acute cortical necrosis.
  • First listed diagnosis: I12.0, Hypertensive chronic kidney disease with stage V chronic kidney disease or end stage renal disease.
  • Second listed diagnosis: N18.5, Chronic kidney disease, stage V.