Occupational Therapy Billing Units

Occupational therapy billing units are a method of time measurement for services rendered. 

A specific amount of time is attached to Current Procedural Terminology (CPT) codes—or occupational therapy billing codes, which explain the services rendered. Usually, one unit is 15 minutes and delineates how much time you spent directly treating your client for the service indicated by the CPT code. 

In this article, we will answer questions you may have about billing insurance as an occupational therapist (OT), like “What are occupational therapy billing units and occupational therapy billing codes?” or “How do you calculate billing units?”  

Reference these occupational therapy billing guidelines, and the occupational therapy CPT codes list included to ensure your occupational therapy billing codes and reimbursement rates are correctly billed when you file claims and get paid by insurance.

What are occupational therapy billing units?

Occupational therapists use billing units for insurance reimbursement. These are typically timed codes indicating how long an OT provided direct occupational therapy to a client. 

There are also untimed codes used for things like evaluations and assessments. 

Timed codes indicate a specific amount of time spent treating your client (via an occupational therapy billing unit). In general, one billing unit is 15 minutes. 

Many, but not all, insurance companies follow the guidelines for billing units set up by the Centers for Medicare and Medicaid Services (CMS), so it’s essential to check your client’s insurance first. 

The CMS guidelines include the “8-minute rule,” which indicates a therapist can charge one billing unit for eight minutes of direct care. The chart below provides a more detailed explanation.

Number of billing units	Amount of time (direct care)
1	8 to 22 minutes
2	23 to 37 minutes
3	38 to 52 minutes
4	53 to 67 minutes

First, check with your client’s insurance company to see if they comply with the 8-minute rule before beginning service. 

To calculate billing minutes, you add up the total minutes of direct care and divide by 15. If you have eight minutes or more of time, you can bill for an additional unit. If you have less than eight minutes of extra time, you can’t bill for an additional unit. 

For example, if you treated a patient directly for 60 minutes, you would divide 60 by 15 and get four. You would then bill for four units. You would also bill four units for treatment that lasted 66 minutes (since the remaining minutes are less than eight). 

Alternatively, if you treated the patient for 72 minutes, you would bill for five units, since there are 12 remaining minutes that are unaccounted for.  

Occupational therapy billing guidelines

OT billing guidelines, while generally the same, are also dependent on your client’s specific insurance. 

As stated above, some insurance companies follow the 8-minute rule, but others may not. 

Occupational therapy billing units should accurately reflect how much time you, as the occupational therapist, have spent directly treating the patient. 

Each timed CPT code also has a specific amount of time attached to it. Most units are billed in 15-minute increments. For example, if you treated a patient for 30 minutes using CPT code 97530 (therapeutic activity), you would bill for two units. 

Billing units directly correlate with the time you spend delivering services. Occupational therapy billing units and occupational therapy billing codes are universal in order to streamline services and reimbursement. 

Incorrectly using billing codes can result in denied claims and loss of payment for your services, so it’s important to pay attention to rules, regulations, policies, and time increments. 

When you are billing for your services, paying attention to the details and double checking for errors can save you a lot of time down the line. 

Here are a few things to confirm you have when billing for your services:

• Correct identifying information (e.g., client’s name, date of birth, insurer’s payer ID, etc.)
• Correct date of care
• Accurately documented units or minutes of services rendered
• CPT codes are correct and accepted by your client’s insurance
• Using correct forms

Occupational therapy units and minutes

The Centers for Medicare and Medicaid Services (CMS) regulate OT units and minutes. 

Understanding and following their guidelines will make things easier for both you and your clients. CMS has billing guidelines on its website that can be helpful in supporting proper documentation of units and minutes. 

You can reference the full CMS billing guidelines or review our abridged insurance guide for OTs. 

We’ve also created an 8-minute cheat sheet for you to reference in a pinch. 

Occupational therapy reimbursement rates

Reimbursement rates for each occupational therapy billing code are set by the Centers for Medicare and Medicaid Services. It is important for occupational therapy providers to stay up to date with these rates and the changes that usually occur at the beginning of each calendar year. 

The latest update for the 2024 calendar year has been controversial due to industry-wide cuts. Despite protest from providers, the CMS made its final ruling in November 2023 and shared a summary of changes to the Medicare fee schedule.

In 2024, CMS has cut reimbursement for occupational therapy providers by 3.4%. The American Occupational Therapy Association (AOTA), alongside physical therapists and speech-language pathologists, are banding together and asking for changes to be made to the reimbursement rates, retroactively. 

Common occupational therapy CPT codes

The AOTA has released a list of commonly used CPT codes for occupational therapists in 2024. 

Although OTs can use many CPT codes, it is important to note that not all codes are covered or reimbursed by insurance companies. Checking with your client’s insurance company ahead of time can help prevent any difficulties associated with occupational therapy billing codes. 

Staying current on CMS changes can also prevent headaches associated with billing. 

Here are a few of the most frequently used billing codes for occupational therapy:

• 97530 (therapeutic activity)
• 97535 (self-care/home management training)
• 97110 (therapeutic procedure)
• 97140 (manual therapy techniques)
• 97129 (cognitive therapeutic interventions)

There are also several telehealth CPT codes, which can be used by occupational therapists who provide care remotely. While these codes are becoming more commonly used, it’s important to check reimbursement rates for these codes.

Using the correct occupational therapy billing units  is critical to ensure you receive the correct reimbursement for services rendered. 

Noting incorrect billing units can affect reimbursement or even be considered fraudulent, which is why you need to understand how occupational therapy billing units work and stay apprised of  the changes released each calendar year. 

It is also important to keep track of reimbursement rates, watch for any cuts, and advocate on behalf of all rehabilitative service providers and your clients—for their continued care and coverage. 

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