So, ICD-10 is a tad more complex than ICD-9. Okay, it’s a lot more complex. In fact, compared to ICD-9, there are about 55,000 more codes in the new set. The good news, though, is that you’ll probably only ever use a handful of them. And one of the best way to prepare for the transition is to create a list of the new codes you know you’re going to need.

Unfortunately, though, identifying the ICD-10 equivalent of an ICD-9 code can be challenging. Because ICD-10 is significantly more specific than ICD-9, there are many instances in which a single ICD-9 code has several ICD-10 correlations. So while a straightforward crosswalking tool isn’t going to give you the most accurate code conversion, there is another way. To get started, download the complete Tabular List of ICD-10 codes here (click the ICD-10-CM PDF Format link under the 2014 release of ICD-10-CM section).

As a rehab therapist, you’ll mostly use chapters 13 (diseases of the musculoskeletal system and connective tissues) and 19 (injury, poisoning and certain other consequences of external causes). Start there, and use your PDF viewer’s search functionality to look up a specific code―or at least to identify some potential ones. You also can perform a keyword search at FindACode.com or use this ICD-9 to ICD-10 conversion tool. However, as I mentioned above, these tools usually will not provide you with an exact match. Rather, they’ll suggest the least specific ICD-10 option, which pretty much defeats the purpose of the new code set. But these kinds of tools will give you a good place to start. Here’s an example: 719.46 (pain in joint, lower leg) is one of the most commonly used ICD-9 codes among PTs. If you enter this code into that conversion tool, you’ll get M25.569 (pain in unspecified knee) as a result. While this may be technically correct, it is most definitely not the right code to use. As a PT, you should at least know in which knee your patient is experiencing pain―and failing to code this very pertinent information may very well result in a claim rejection.

To find the most correct code, open the Tabular List and go to chapter 13, which is where all the M codes reside. Then, find M25.56 (the knee pain category) and read through the subsequent options that include laterality (i.e., M25.561: pain in the right knee and M25.562: pain in the left knee.) Additionally, if you can code for the specific condition that is causing your patient’s pain, even better. To continue with the above example, if you determine that your patient is suffering from patellar tendinitis, you would use either M76.51 or M76.52 (patellar tendinitis, right or left knee, respectively) instead.

While you’re browsing the new code set, pay close attention to the instructions at the top of each chapter and category. In some cases, you may need to apply an external cause code or a seventh character. For instance, at the beginning of chapter 13, you’ll see the following: “Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition.” In other words, if you know additional details about what caused your patient’s condition, you should account for them using supplemental external cause codes, which can be found in Chapter 20. (Please note, however, that there is no national requirement for external cause codes, so in most cases submitting them is optional.) If your knee pain patient developed his or her patellar tendinitis as a result of running on a treadmill, for example, you’d indicate that by adding the supplemental code Y93.A1 (activity, treadmill).

If you prefer your how-tos in step form, you’re in luck. Here’s how to find the correct ICD-10 code in four easy steps:

  1. Type the ICD-9 code you’d normally use into a conversion tool to get an ICD-10 code to use as a starting point.
  2. Review the Tabular List to determine if there are codes with greater levels of specificity available. (Be sure to pay attention to chapter and category headings for additional coding instructions.)
  3. If you can, code for the actual condition (e.g., patellar tendinitis) instead of the result (e.g., knee pain).
  4. If instructed to do so, use a pertinent external cause code, which can be found in chapter 20 of the Tabular List.

What are your top five most commonly used ICD-9 codes? Have you found their ICD-10 equivalents yet? If so, what advice do you have for other therapists compiling their lists? Share your thoughts―and questions―in the comments section below.