In the world of medical billing, diagnosis codes are as essential as morning coffee! That’s because the international classification of diseases (ICD) established treatment diagnosis codes that help to describe your patient’s condition with precision—think “unspecified injury of left shoulder and upper arm, initial encounter” instead of just “patient’s arm hurts!”
In this article, discover common occupational therapy ICD-10 codes that will help providers deliver the right therapy services—and get paid for it, too!
What is ICD-10 Coding?
ICD-10—International Classification of Diseases, Tenth Revision—is a standardized system to accurately document and communicate patient conditions and treatments used by healthcare professionals, including occupational therapists (OTs). The World Health Organization (WHO) published the first version in 1990, though the United States didn’t switch over until 2015. With approximately 155,000 ICD-10 codes compared to ICD-9’s 17,000, the transition added the ability to code to the highest level of specificity.
ICD-10 codes for occupational therapy and other practices are alphanumeric, typically consisting of a letter followed by a number (e.g. J18.9). The first character indicates the disease category, and the other characters refine the diagnosis. In OT, these codes help identify underlying conditions (e.g. M17: osteoarthritis of knee), document functional limitations (e.g. F00-F99: mental, behavioral, and neurodevelopmental disorders), track progress and outcomes (to justify continued therapy), and ensure accurate reimbursement.
ICD-10 PCS vs. ICD-10-CM
The ICD-10 system enables more detailed tracking of diagnoses and procedures with improved clinical accuracy and specificity. It’s further separated into ICD-10-CM and ICD-10-PCS, with the former applying to clinical and outpatient coding and the latter to inpatient hospital settings. ICD-10-CM codes have three characters (plus decimals) like M54.2, while ICD-10-PCS uses seven-character codes like 047K0ZZ.
ICD-10 Codes and Medical Necessity
A big payer pet peeve is “medical necessity”—responsibility for proving that medical services or treatment provided was necessary to the patient’s overall healthcare needs, and the most beneficial versus other therapies or treatments. Proving medical necessity helps avoid unnecessary treatment, in addition to preventing fraud in billing.
Using correct coding is also important. A vague code might not adequately support the medical necessity of the service, potentially leading to claim denials. OTs should also thoroughly document the patient’s functional limitations, treatment plan, and expected outcomes to strengthen the justification for medical necessity.
Most Common Occupational Therapy ICD-10 Codes
Occupational therapy addresses many conditions that can impact a person’s ability to perform everyday activities. While often associated with children and older adults, OT can benefit people of all ages.
Some conditions treated by OTs include developmental delays, cerebral palsy, autism spectrum disorder, work injuries, musculoskeletal disorders like arthritis and carpal tunnel syndrome, mental health conditions like anxiety and depression, stroke, spinal cord injuries, and cognitive issues like dementia or Alzheimer’s disease. Many of these conditions can benefit significantly from therapies that improve motor skills, self-care abilities, mobility, coordination, and pain management.
OT can also benefit patients with burn injuries (scar management; range of motion), vision impairment (performing daily tasks safely and independently), and for strengthening of muscles in preparation for surgery.
Common occupational therapy ICD-10 codes include:
Motor Skills, Weakness, Incoordination and Falls
- F82 Specific developmental disorder of motor function
- M62.81 Muscle weakness (generalized, globally decreased)
- R27.8 Other lack of coordination (including Dysgraphia, Dysmetria, Dyspraxia)
- R29.3 Abnormal posture
- R26.81 Unsteadiness on feet
- R26.2 Difficulty in walking, not elsewhere classified
- R29.6 Repeated falls
- Z91.81 History of falling
How to Look Up ICD-10 Codes
Accurate coding ensures clear communication between payors and providers, better patient care, and proper billing for reimbursement, as well as data collection to inform public health efforts.
To look up ICD-10 codes for occupational therapy, you can utilize various online tools like the CDC’s ICD-10-CM Look Up Tool and enter relevant keywords, diagnoses, or medical conditions to retrieve corresponding ICD-10 codes. The American Occupational Therapy Association also offers diagnosis coding resources for members.
For a more convenient experience, many electronic health record (EHR) systems include built-in code search functionality, enabling quick and efficient access to the required ICD-10 codes for accurate medical reporting and billing.
Occupational Therapy Billing Best Practices
In medical billing, accuracy is essential. But mistakes do happen. One way to avoid them is to know which are most common and the billing best practices to have in place.
❌ Errors in demographic information (names, dates of birth, insurance ID numbers)
✅ Double-check everything! Bonus points if you automate this process.
❌ Coding errors (upcoding or undercoding, choosing the wrong codes, missing modifiers).
✅ Stay up-to-date on the latest coding guidelines. Avoid vague or unspecified codes. Consider using software that will check for errors.
❌ Lack of documentation or missing signatures.
✅ Ensure documentation is accurate and thorough and that both the OT and the patient (or guardian) have signed anything where required.
❌ Not verifying patient eligibility or prior authorization.
✅ Always confirm insurance coverage before providing services and if prior authorization is required.
❌ Not billing correctly for telehealth services.
✅ If you provide OT services remotely, use the appropriate modifiers.
Ongoing training on billing and coding best practices can help minimize errors and optimize reimbursement. Billers should also be aware of payer rules and coverage limits. Specialized billing software can automatically scan for errors, freeing billers from tedious tasks and ensuring accuracy, which allows for smoother operations and peace of mind.
Work Smarter, Not Harder with Specialized Billing Software
Now you know what ICD-10 coding is, why it’s important, and how to find the right codes for common OT treatment scenarios.
ICD-10 coding promotes clear communication between providers and insurers while supporting accurate and detailed documentation to justify medical necessity, allowing proper reimbursement. By understanding the structure and purpose of ICD-10 codes, OTs can optimize patient care and practice management.
Make coding and billing easier with specialized billing software for OT, PT, and SLP practices that automates time-consuming processes and reduces errors.
Frequently Asked Questions
What’s the difference between ICD-10 and CPT codes?
CPT codes specify what was done (the services or procedures performed), while ICD-10 codes tell you why it was done (the patient's diagnosis).
Who has to use ICD-10 codes?
Physicians, nurses, and other healthcare providers use them. Insurance companies, medical billers, and healthcare regulators must also know the ICD-coding system.
What are encounter codes, or the seventh character in ICD-10?
Some codes include an additional seventh character to specify or denote the initial encounter, subsequent encounter, or sequela (a condition caused by a previous disease or injury).
What is the billing modifier used for OT?
OT services may require modifiers such as:
GO. Service delivered by an OT or under an outpatient OT plan of care.
CO. 10% or more of the outpatient service is performed by an occupational therapist assistant (OTA).
59. Clarifies a separate and distinct service from other services or procedures performed during the same session.
