How to Pick the Right ICD-10 Code for Depression

Whether as a result of the pandemic, and the isolation that many people experienced, or from new focus from regulators, mental health and depression have been at the forefront of care—both for patients and providers. And although it is generally not a diagnosis patients are referred to rehab therapy for, it can still affect many of the patients coming to therapy. A report from Versus Arthritis found that depression is four times more common in patients with chronic pain—a fact that anyone treating musculoskeletal (MSK) pain is likely all too familiar with.

This is why knowing the ICD-10 code for depression, when to use the ICD-10 code, and how best to apply it is crucial for clinicians looking to treat the whole patient while accurately completing an evaluation and successfully being reimbursed for the claim. 

What is Depression?

As with any medical term, there are layman's and medical definitions. For a patient to be clinically diagnosed with depression a medical doctor needs to assign this diagnosis. For clear and concise criteria as to what depression is, the Diagnostic and Statistical Manual of Mental Disorders (DSM V) has a set list of criteria. Depression is defined as having five or more of the following symptoms present during the same two-week period that represents a change from previous functioning. Additionally, at least one of the symptoms is either described as a depressed mood or loss of interest or pleasure in doing things.

Using the National Institutes of Health resource, the criteria are as follows:

1. A depressed mood that is indicated by subjective report or observation by others (in children and adolescents, it can be an irritable mood).
2. A loss of interest or pleasure in almost all activities that are indicated by subjective report or observation by others.
3. Significant (more than 5 percent in a month) unintentional weight loss/gain or decrease/increase in appetite (in children, failure to make expected weight gains).
4. Sleep disturbance (insomnia or hypersomnia).
5. Psychomotor changes (agitation or retardation) are severe enough to be observable to others.
6. Tiredness, fatigue, low energy, or decreased efficiency with which routine tasks are completed.
7. A sense of worthlessness or excessive, inappropriate, or delusional guilt (not merely self-reproach or guilt about being sick).
8. Impaired ability to think, concentrate, or make decisions—indicated by subjective report or observation by others.
9. Recurrent thoughts of death (not just fear of dying), suicidal ideation, or suicide attempts.

But instead of combing through 1100 pages of psych-related diagnoses, rehab therapists have tools at their disposal to screen for depression in current and incoming patients. If you think your patient may be depressed, administer an approved screening tool like the Patient Health Questionnaire-2 (PHQ-2) or its larger counterpart, the PHQ-9—a good EMR will have this tool linked in your documentation workflow. If the survey returns a positive result, the patient should be referred to the appropriate medical professional. And if care continues, appropriate documentation should correspond with these results, the subsequent referral, and any follow-up interventions that have ensued.

What is the ICD-10 Code for Depression?

Depression is found in chapter V under letter F of the ICD-10 coding structure, and new codes are effective October 1, of each year. Specifically, the ICD-10 code for a single episode of major depressive disorder (unspecified) is code F32.9, but in the ICD-10 coding structure, specificity is the name of the game, be sure you affix the correct diagnosis as specified by the referring physician. For that reason, depression can be found in six more codes ranging from F32.0 to F32.9:

• F32.0: Major depressive disorder, single episode, mild;
• F32.1: Major depressive disorder, single episode, moderate;
• F32.2: Major depressive disorder, single episode, severe without psychotic features;
• F32.3: Major depressive disorder, single episode, severe with psychotic features;
• F32.4: Major depressive disorder, single episode, in partial remission; and
• F32.5: Major depressive disorder, single episode, in full remission.

When Would Rehab Therapists Use ICD-10 for Depression?

Only on rare occasions would physical therapists, occupational therapists, or speech-language pathologists use the ICD-10 code for depression as a primary diagnosis—maybe even never for most—but that does not mean the code doesn’t have a place in the plan of care or initial evaluation. If a patient’s depression diagnosis is such that it can negatively impact the course of care, affect the patient’s prognosis for meeting their goals, or result in future hospital (or other outside services) admissions, then depression should be applied as a secondary diagnosis for this patient. 

Why? Well, recall that there are now three levels of complexity for PT and OT evaluations, and SLPs have additional evaluation components to be aware of. For moderate to high complexity cases, an ICD-10 code for depression would be well suited to these types of patients.

John Wallace, PT, MS, OCS, Senior VP of Member Value and Chief Business Development Officer of RCM at WebPT, recently tackled the secondary diagnosis problem in his 2024 Combined Sections Meeting (CSM) presentation “People, Processes, and Internal Controls: Key Elements to Scaling Your Billing Operations.” Wallace recounted that far too many clinicians are short-changing themselves and their patients by affixing a low complexity evaluation CPT code to patients who would be better served as moderate or even high complexity—this could apply to cases of depression or even an additional musculoskeletal diagnosis like rheumatoid arthritis. To address the problem, Wallace encouraged clinicians to code patients' secondary and tertiary diagnoses more accurately. By doing so, he stated this will enable clinicians to better advocate for their value and be ready for increased emphasis by insurance payers on value-based care.

What Are Good Resources for Rehab Therapists to Find ICD-10 Codes?

In his presentation, Wallace encouraged rehab therapists to use their current EMR’s tools to search for the appropriate diagnosis, or—if necessary—look to outside assistance in the form of the free database ICD10data where over 69,000 codes can be searched. 

Are the ICD-10 Codes for Depression and Anxiety the Same?

Although most patient charts may state a patient has a diagnosis of anxiety and depression, their specific codes are not the same. Keeping to the specifics, the diagnosis of anxiety has its own code, starting with F40. But just as depression has several other applicable ICD-10 codes, so does anxiety—so we created a separate post to go into more detail.

Does postpartum depression apply to patients with MSK pain?

As many rehab therapists can attest, depression plays a large role in the care of patients experiencing pain—more so in cases of chronic pain. For a slew of different factors, many mothers experience ongoing MSK pain after pregnancy, which places them at increased risk of developing postpartum depression. In this instance, if the treating therapist feels the postpartum depression affects the mother's postpartum care, then diagnosis code F53.0 should be applied as a secondary or tertiary diagnosis. 

How Can Technology Help with ICD-10 Codes?

Aside from knowing how to assign the correct ICD-10 code to each patient’s case, there are many automated workflows that the best EMRs have built into their software. For example, WebPT uses an intuitive purpose-built Practice Experience Management platform for rehab therapists that eliminates extra clicks and the need to leave your software and do a Google search. After all, in today’s age, shouldn’t the software you use be an asset in creating the ideal practice experience?