PT Primer for Coding Pain and Injuries in ICD-10

When ICD-10 finally arrived at the doorsteps of clinics in the US, the methodology to code diagnoses was turned on its head. No longer did best practice dictate for evaluating therapists to assign as many applicable codes as they could to a case (see ICD-9). Instead specificity and accuracy of coding was the supreme directive for ICD-10. Since that change, rehab therapists have become quite adept at assigning diagnosis codes in their EMRs, but at times we fall prey to habits and perhaps assign pain related diagnosis codes too often, or not enough depending on the situation. To be sure you are coding the correct ICD-10 for pain or injuries with your patients, here are a few pointers to steer you in the right direction.

Coding ICD-10 for Pain

You’ve probably heard the old real estate cliché, “Location is everything!” But that golden drop of wisdom doesn’t just apply to zip codes and cross streets. For physical therapists, location is probably the most important factor to consider when selecting the ICD-10 code that best describes a patient’s pain. Why? Because when it comes to coding for an anatomical site, specificity is key. 

In ICD-10, specific codes for pain are used to differentiate anatomical region as well as laterality. In fact, more than a third of the expansion from ICD-9 is due to the addition of separate codes for laterality (e.g., left, right, or bilateral) which has all helped to boost the accuracy of reporting within patients’ medical records and improve communication between providers.

Finding the Right ICD-10 for Pain

If combing a dense database sounds like a good time to you, check out this resource where you’ll find pain codes in three different places within the full tabular list: the body system chapters, the signs and symptoms chapter, and category G89 (Pain, not elsewhere classified) in the nervous system chapter. However, the majority of PT-applicable pain codes appear in chapter 13—a.k.a. the musculoskeletal or “M'' code chapter. Examples of common musculoskeletal pain codes include M54.51 (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).

Here’s the kicker, though: if you know what is causing the pain, you should code for the underlying condition instead—although in some cases, it might be appropriate to submit both codes. ICD-10-CM guidelines state that if the cause of the pain is known—in many cases the specific injury—the injury code should be used instead of the pain code. However, if the purpose of the encounter is to manage the pain due to the injury (rather than the injury itself), then you should assign a pain code and sequence it first. For a detailed example of this type of scenario, check out this page.

Coding for Injury

Although ICD-10 offers much greater specificity—and consequently, a much larger library of codes—for coding injuries, many of the injury coding guidelines that exist for ICD-9 also apply to ICD-10. But there are a few important differences, including the addition of seventh character extensions, which I’ll explain below.

You will find injury codes in chapter 19 of the tabular list. As you search for the code that best—and most specifically—represents a patient’s injury, you should consider the following factors, as noted here:

1. Episode of care.

This is where the seventh character comes in. If a particular code requires that you attach a seventh character, you will see instructions to do so within the tabular list. As this resource explains, there are three different options:

• A - Initial encounter: This means the patient is receiving active treatment for the injury (e.g., surgery, emergency room treatment, or evaluation and treatment by a new medical professional).
• D - Subsequent encounter: This indicates that the patient is receiving routine care for the injury during the healing or recovery phase (e.g., cast removal, medication adjustment, or aftercare and follow-up). Please see this post on aftercare codes (e.g., the “Z” codes) for injury aftercare. 
• S - Sequela: This indicates that the injury has caused another condition for which the patient is seeking treatment. 

2. Injury site.

Within chapter 19, injuries are organized by anatomical site instead of category, which makes it much easier to select the most specific site possible.

3. Etiology.

Whenever possible, you should account for the cause of the injury (e.g., sports, motor vehicle accident, or slip and fall)  and/or the activities leading up to the injury by submitting applicable external cause codes along with the injury code. We’ll talk more about external cause codes in a blog post later this month, but for now, just know that you will find them in chapter 20.

4. Place of occurrence.

Again, 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 will also find these codes in chapter 20.

In many ways ICD-10 helped to modernize American healthcare models, and improve practice management for rehab therapy practices in their care delivery and reporting for care coordination and reimbursement purposes. If you are looking for a deeper dive into ICD-10 than this PT primer for coding pain and injuries, check out our free ICD-10 checklist.