HCPCS Code S9129: Occupational Therapy, in the Home, Per Diem

Read about HCPCS code S9129 occupational therapy in the home per diem, including documentation and billing guidelines to improve your practice.

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## **What is HCPCS code S9129?** HCPCS code S9129 is defined as "Occupational therapy, in the home, per diem." This service may also be associated with physical therapy or per diem occupational therapy, depending on the patient’s condition and individual needs. This code falls under the category of Miscellaneous Supplies and Services as maintained by the Centers for Medicare & Medicaid Services (CMS). HCPCS Level II codes, including S9129, are used to report medical services and supplies not identified by the CPT codes (Level I), specifically for services such as therapy in the home, home healthcare therapies, medical equipment, and supplies. The purpose of HCPCS codes like S9129 is to standardize claims submission for Medicare and Medicaid, ensuring consistent processing of therapy, assistance, and other services. This code is part of the temporary national codes categorized in the range S0012 to S9999. The code is maintained and used by CMS for billing and claims processing, whether provided in a residence, assisted living facility, or home per diem setting.

## **HCPCS code S9129 documentation requirements** While CMS does not mandate additional documentation unique to this code, providers must maintain records that justify the service in line with Medicare standards. Required documentation should include: - Practitioner’s assessment of the patient’s condition - Detailed plan of care with treatment goals and interventions - Progress notes demonstrating response to therapy - Evidence that services were provided in the home setting - Patient diagnoses relevant to occupational therapy needs - Medical plan of care signed and dated by the ordering provider - Timely, accurate, and complete records to support compliance and medical review

## **S9129 billing requirements** Key billing requirements for S9129 include: - Submit claims using the appropriate CMS form (CMS-1500 or UB-04, depending on setting) - Bill per visit or per diem, not by time increments - Include appropriate revenue codes with the claim - Report billing units as one day of service, not by minutes - Ensure compliance with payer-specific timely filing requirements - Include the National Provider Identifier (NPI) for both rendering and billing providers - Follow Medicare, Medicaid, and commercial payer guidelines to avoid denials

## **Other related codes** Other related codes to HCPCS code S9129 are: - **G0152**: Services performed by a qualified occupational therapist in the home health or hospice setting (billed in 15-minute increments). - **G0158**: Services by a qualified occupational therapist assistant in the home health or hospice setting (each 15 minutes). - **S9122**: Home health aide or certified nurse assistant, providing care in the home; per hour - CPT codes for occupational therapy evaluations and re-evaluations such as 97165 (low complexity evaluation), 97166 (moderate complexity), 97167 (high complexity), and 97168 (re-evaluation).