Introduction

Obsessive-Compulsive Disorder (OCD) presents unique challenges for both patients and clinicians. Characterized by distressing obsessions and time-consuming compulsions, accurate diagnosis and documentation are essential for effective treatment and billing.

This guide walks mental health professionals through how to correctly code OCD and related disorders using the ICD-10-CM classification system. We’ll cover specific codes, documentation tips, common errors, and official guidance to help you code confidently and compliantly.

Why Accurate ICD-10-CM Coding for OCD Matters

Precise coding is critical for:

• Clinical Clarity: Ensures consistent diagnosis across providers

• Billing and Reimbursement: Prevents claim denials

• Treatment Planning: Informs therapy and medication decisions

• Quality Reporting & Research: Supports population health data

• Compliance: Meets HIPAA and payer documentation requirements

Primary ICD-10-CM Codes for OCD (F42 Series)

OCD and related disorders fall under ICD-10-CM code block F42. The general code F42 is not billable—you must use a more specific sub-code.

Common OCD-Related ICD-10 Codes:

• F42 – Obsessive-Compulsive Disorder (Category only – not billable)

• F42.2 – OCD (Mixed obsessional thoughts and acts) → Primary billable code for OCD

• F42.3 – Hoarding Disorder

• F42.4 – Excoriation (Skin-Picking) Disorder

• F42.8 – Other OCD-related disorder (e.g., obsessional jealousy, Koro)

• F42.9 – OCD, Unspecified → Use only when documentation lacks detail

Key Notes:

• Use F42.2 as the standard OCD diagnosis in the U.S.

• Use F42.3 and F42.4 only when diagnosed as distinct disorders

• Use F42.8 and F42.9 sparingly and only when clinically necessary

Understanding OCD Specifiers (Not Separate Codes)

ICD-10-CM doesn’t include specific codes for DSM-5 specifiers, but you should document them clearly in your notes.

Insight Specifier:

• Good or Fair Insight: Patient recognizes their thoughts are likely untrue

• Poor Insight: Patient believes their OCD thoughts are probably true

• Absent Insight / Delusional Beliefs: Patient is convinced their thoughts are true

💡 All levels still use F42.2. Document insight level clearly in your clinical narrative.

Tic-Related Specifier:

• Use if the patient has a current or past tic disorder (e.g., Tourette’s)

• Code OCD with F42.2 and code the tic disorder separately:

  • F95.2 – Tourette’s Disorder

  • F95.1 – Chronic Motor Tic Disorder

Hoarding vs. Skin-Picking vs. OCD

Sometimes, patients with OCD have hoarding or skin-picking behaviors. Here’s how to distinguish them:

• Use F42.3 (Hoarding) or F42.4 (Excoriation) only when full criteria are met

• If these behaviors are simply symptoms of OCD, document them in the note but code only F42.2

• Both codes (e.g., F42.2 + F42.3) can be used together when both conditions are diagnosed

📝 Clear documentation helps determine if it’s a symptom or a separate diagnosis.

Coding OCD Across the Lifespan

ICD-10-CM uses the same codes for all ages, but documentation should reflect age-appropriate context.

Key Points:

• In children, ensure symptoms meet full OCD criteria—not just age-typical rituals

• PANDAS/PANS: Use F42.2 for OCD, and separately code the medical condition (e.g., strep infection)

• Comorbidities: Code additional diagnoses like:

  • F90.x – ADHD

  • F41.1 – Generalized Anxiety Disorder

  • F32.x/F33.x – Depression

🎯 Sequence codes based on the main reason for the visit.

Best Practices for Documenting and Coding OCD

1. Use Specific Codes

   • Always use a full code like F42.2, never just F42

2. Document the Diagnosis Clearly

   • Use specific terminology: “Obsessive-Compulsive Disorder,” “Excoriation Disorder,” etc.

3. Include Specifiers When Relevant

   • Describe insight level or tic history in your narrative

4. Differentiate Look-Alike Conditions

   • OCD is not the same as Obsessive-Compulsive Personality Disorder (OCPD → F60.5)

5. Avoid F42.9 Unless Absolutely Necessary

   • Only use when documentation lacks enough detail for a more specific code

6. Link Diagnosis to Services

   • Ensure the OCD code (F42.2) is connected to the CPT code on your claim (e.g., psychotherapy, E/M)

7. Diagnose with DSM-5 → Code with ICD-10-CM

   • DSM-5 code 300.3 for OCD maps to F42.2

8. Work With Your Coding Team

   • Use documentation tools like Nudge to prompt for insight level, tics, and clarity

Common Mistakes to Avoid

❌ Using F42 (category code) instead of F42.2 (billable code)

❌ Confusing OCD (F42.2) with OCPD (F60.5)

❌ Overusing F42.9 even when the chart clearly documents OCD

❌ Missing comorbid diagnoses like anxiety or tic disorders

❌ Separately coding symptoms like insomnia if they’re part of OCD

❌ Ignoring Excludes notes when symptoms belong to other disorders

❌ Incorrect code sequencing on claims

❌ Misclassifying hoarding or excoriation as OCD symptoms when they're actually distinct diagnoses

Trusted Resources to Stay Compliant

Use these references to stay up to date:

• ICD-10-CM Official Guidelines for Coding and Reporting

• ICD-10-CM Tabular List (F42 section)

• APA DSM-5-TR

• AHA Coding Clinic® for ICD-10-CM

• CMS.gov for ICD-10 and coding updates

• Payer-specific LCD/NCD policy guidelines

Conclusion

Accurate ICD-10-CM coding for Obsessive-Compulsive Disorder (F42.2) is foundational for clinical care, documentation quality, and reimbursement.

By consistently using the right codes, documenting DSM-5 specifiers, and avoiding common pitfalls, you’ll ensure your records are both clinically sound and audit-proof.

Tools like Nudge can help streamline this process—guiding clinicians to document what matters, when it matters most.