ICD-10 has five times as many diagnosis codes as its predecessor, ICD-9. And while that might sound scary at first, as a physical therapist, you really only need to know a small fraction of the new code set. Today, let’s talk about two of the major coding categories relevant to rehab therapists: pain and injury. After all, that’s probably why most of your patients are seeking your services in the first place.


One of the main differences between ICD-9 and ICD-10 is the latter’s greater level of specificity—more specifically (ha!), its inclusion of codes designating region and laterality. For physical therapists, location is probably the second most important factor to consider when choosing which ICD-10 code to select—after considering the cause of the patient’s pain, of course. While this additional level of specificity is an asset of the ICD-10 code set, it also means that once it goes live, you will no longer be able to get by using many of the ICD-9 catch-all codes of yesteryear (otherwise known as unspecified codes).

Let’s take limb pain, for example. In her aptly-titled article, “Pain in limb 729.5 doesn’t cut it in ICD-10,” author Bernie Monegain explains that there are more than 30 codes that fall into the pain-in-limb category—and these codes account for everything from region (e.g, upper arm, thigh, and lower leg) to laterality (e.g., left and right). Centers for Medicare and Medicaid (CMS) reports that more than 33% of the increase in ICD-10 codes is due to the addition of new and distinct laterality codes.

According to this article, most of the pain codes are located in three places within the tabular list: the body system chapters, the signs and symptoms chapter, and in category G89 (pain, not elsewhere classified) in the nervous system chapter. However, you can find the most relevant pain-related codes for physical therapists in Chapter 13 (the musculoskeletal or “M” code chapter). The most common examples of musculoskeletal pain codes include M54.5 (low back pain), M25.512/M25.511 (pain in left shoulder/pain in right shoulder), and M25.551/M25.552 (pain in right hip/pain in left hip).

However, if you know what is causing your patient’s pain, you should always code for that underlying condition instead of or in conjunction with the code for pain. According to this article, “The ICD-10-CM guidelines state that if the cause of the pain is known, you should assign a code for the underlying diagnosis, not the pain code. However, if the purpose of the encounter is to manage the pain rather than the underlying condition, then you should assign a pain code and sequence it first.” For a detailed example of this type of scenario, check out this site.


You’ll find injury codes in chapter 19 of the tabular list. While many of the injury coding guidelines that apply to ICD-9 also apply to ICD-10, there are a few important distinctions—one of which is ICD-10’s addition of the seventh character extension, which specifies episode of care. If a particular code requires that you attach a seventh character, you’ll see instructions to do so within the tabular list. According to this article, there are three different seventh character extensions:

  1. A – Initial encounter. This character applies if the patient is receiving active treatment for his or her injury (e.g., surgery, emergency room treatment, or evaluation and treatment by a new medical professional).
  2. D- Subsequent encounter. This code applies if the patient is receiving routine treatment for his or her injury during healing or recovery (e.g., cast removal, medication adjustment, or aftercare). Note that you should not use aftercare codes for injury aftercare. Instead, attach the seventh character “D” to the applicable acute injury code.
  3. S – Sequela. This code applies if the patient is receiving treatment for a condition that occured as a result of the original injury. According to the article cited above, this character applies to “complications or conditions that arise as a direct result of an injury, such as scar formation after a burn. The scars are sequela of the burn. When using extension S, it is necessary to use both the injury code that precipitated the sequela and the code for the sequela itself. The S is added only to the injury code, not the sequela code.”

When selecting the correct code that most specifically represents your patient’s injury, you should also consider the following (as noted here):

  • Injury site. Within chapter 19 of the tabular list, injuries are organized by anatomical site, which makes it much easier to select the most specific injury site possible.
  • Etiology. You should always do your best to account for the cause of your patients’ injuries (e.g., sports, motor vehicle accident, or slip and fall) and/or the activities leading up their injuries by submitting an appropriate external cause code (along with the appropriate injury code). You can find cause codes in chapter 20 of the tabular list.
  • Place of occurrence. If you know where the injury occurred (e.g., gym, athletic field, or swimming pool), you should code for it using an appropriate place of occurrence code. You can also find these codes in chapter 20.


Looking for a way to connect the ICD-10 dots? Here’s an example from CMS:

Description of injury: Left knee strain occurred on a private recreational playground when a child jumped off of a trampoline and landed incorrectly.

  • Injury code: S86.812A (strain of other muscle(s) and tendon(s) at lower leg level, left leg, initial encounter)
  • External cause code: W09.8XXA (fall on or from other playground equipment, initial encounter)
  • Place of occurrence code: Y92.838 (other recreation area as the place of occurrence of the external cause)
  • Activity code: Y93.44 (activities involving rhythmic movement, trampoline jumping)