Occupational Therapy Billing Units: A Complete Guide

According to the American Occupational Therapy Association (AOTA) defines occupational therapy as “using daily activities in a therapeutic manner to support client participation”. Occupational therapy billing units (OT billing units) are a necessary part of clinical practice, providing a foundation for accurately documenting and billing for services. Accurate billing is important to sustain practice operations and meet insurance requirements, helping providers to deliver excellent care and receive accurate reimbursement from payers.

This guide explores occupational billing units in detail, including types, challenges, best practices, and key coding rules to help OTs optimize financial and operational practices.

Understanding OT Billing Units

OT billing includes two primary types of codes: timed and untimed, which dictate how therapists should bill for their services.

• Timed Codes: Generally applied to treatment procedures and follow the “8-minute rule.” For services to be billable, treatment duration must be at least 8 minutes, and billing units are counted in 15-minute increments:
  • 1 Unit: 8–22 minutes
  • 2 Units: 23–37 minutes
  • 3 Units: 38–52 minutes
  • 4 Units: 53–67 minutes
• Untimed Codes: Typically used for evaluations, untimed codes allow therapists to bill one unit per session, regardless of its duration.

Common Evaluation Codes

OT evaluations are categorized based on complexity:

• CPT Code 97165 (Low Complexity): 30 minutes, brief medical history, 1-3 performance deficits.
• CPT Code 97166 (Moderate Complexity): 45 minutes, expanded medical history, 3-5 performance deficits.
• CPT Code 97167 (High Complexity): 60 minutes, detailed medical history, 5+ performance deficits.
• CPT Code 97168 (Re-evaluation): Conducted to adjust the plan of care according to the patient’s progress.

Frequently Used OT CPT Codes

Some of the most commonly applied CPT codes in occupational therapy include:

• CPT Code 97530 (Therapeutic Activity): Dynamic activities for functional improvement.
• CPT Code 97535 (Self-Care/Home Management Training): Training in ADL/IADL skills, safety, and assistive technology.
• CPT Code 97112 (Neuromuscular Re-education): Focuses on movement, coordination, and balance.
• CPT Code 97110 (Therapeutic Exercise): Targets strength, endurance, and flexibility.
• CPT Code 97140 (Manual Therapy): Techniques like mobilization and manipulation.
• CPT Code 97537 (Community/Work Reintegration): Real-world skill training, such as shopping and work task analysis.

Accurate Documentation for OT Billing

Detailed documentation helps support the medical necessity of OT services, which is vital for reimbursement and patient wellbeing. Essential elements include:

• Correct codes and CPT descriptions
• Goals addressed during the session
• Patient’s progress toward goals
• Reasoning for continued services

Documentation must meet HIPAA requirements for patient privacy, and it is crucial to submit all records promptly, especially if requested for an audit.

Avoiding Common OT Billing Errors

Accurate billing reduces the risk of claim denials and reduces delays in reimbursement. To reduce the risk of denials, look out for these frequent billing mistakes include:

• Incorrect patient information (e.g., birthdate, insurance details)
• Incorrect claim forms
• Insufficient documentation
• Duplicate claims for the same day

Auditing and reviewing documentation regularly can help identify and prevent these issues, reducing delays in reimbursement.

Tips for Successful OT Billing

OT billing is an ongoing challenge, but with the right strategies and education you can help ensure your billing is accurate and reimbursement is on schedule. You should always try to:

• Stay Informed: Annual updates to CPT codes and billing requirements are published by CMS, AOTA, and AMA, making it important to review these changes.
• Check Modifier Requirements: Some services require specific modifiers; confirm these with insurers to avoid claim denials.
• Streamline Billing Processes: Using specialized tools or systems can simplify managing claims, documentation, and payments, helping reduce errors and improve efficiency.

While OT billing units can be challenging, thorough documentation, accurate coding, and awareness of insurance requirements will help make for a smoother process. Staying current with updates and using available resources can assist occupational therapists in maintaining compliance and optimizing reimbursements.

Disclaimer: The following information is not meant to serve as a recommendation for how your organization bills on a patient-by-patient basis. You can use this information to help determine what billing policy is right for your organization, but always refer to your organization’s guidelines.