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Using Unit Billing and multiple service codes

Using Unit Billing and multiple service codes

Unit Billing allows you to bill service codes in units, rather than or in addition to duration. You can also use multiple service codes for a single appointment. These options offer flexibility when creating claims and superbills.

In this guide, we’ll cover: 

Using Unit Billing:

Using multiple service codes: 


Important: Unit billing requirements vary by insurance payer. We recommend reaching out to your insurance payer(s) to check their requirements before submitting a claim.

Using Unit Billing

Setting up Unit Billing

To bill an appointment by unit, first enable Unit Billing for the service code(s) in question. To do this:

  • Navigate to Settings > Billing & Services > Services
  • Click the service you want to bill by unit 
  • Check Bill this code in units 


  • Enter the Rate per unit


Note: If the Rate per unit is adjusted for an existing service, this change will only be applied to new appointments and won’t update existing appointments. To update existing appointments, see Editing an appointment

  • Enter the Default Duration


Note: The Default Duration is the amount of time that will be blocked off in the calendar when you schedule a session with this service code. The Default Duration won’t automatically update the amount of units billed for the service code. The default number of units will be 1, which can be edited from your calendar. 

  • Click Save 

For more information on managing your service codes, see Creating and using service codes and products.

Billing an appointment in units 

When scheduling a unit-billed appointment on your calendar, you’ll have the option to edit the following details: 

  • Services
  • Modifier(s), if enabled 
  • Units 
    • You can manually enter the number of units, including partial units up to one decimal place 
    • To avoid claim rejections, don’t enter leading zeros (0.5) or trailing zeros (1.0) 
  • Rate per unit 
  • Total fee
    • The fee will automatically update when the number of units or rate per unit is adjusted


If the fee is manually adjusted, the rate per unit field will be disabled. You can reset this by hovering over the disabled field and clicking Reset total rate:


Note: If the rate per unit field is disabled, you won’t be able to adjust the field, and the fee will no longer update automatically when adjusting the number of units. 

You can also edit a unit-billed appointment on a client’s Billing page. To do this: 

  • Navigate to the client’s Billing page
  • Click Manage > Edit details next to the appointment


  • Adjust the service code, number of units, rate per unit, modifier(s), or fee


  • Click Save 

For more information on editing an appointment’s details, see Appointment level billing changes. 

Once a unit-billed service has been added to an appointment, the units will automatically populate in box 24g on claims:


On superbills, you’ll see this in the Units column: 


Important: If you need to update an appointment’s details after a claim has been created, we recommend that you make the updates directly to the appointment, and then delete and recreate the claim. If edited directly on the claim, the details won’t update in your account, which can cause discrepancies in your billing. If deleting a claim, make sure to save the Clearinghouse Reference # and Payer Claim # (if applicable) before deleting. To update a superbill, you can make the necessary changes in your account and then delete and recreate the superbill.

Adding a unit-billed service as a client’s default service 

To add a unit-billed service as a client's default service: 

  • Navigate to the client’s Overview page 
  • Click Edit > Billing and Insurance
  • Scroll to Client Default Services


  • Select the service code and enter the Rate Per Unit  


  • Click Save Client 

When creating a new appointment for the client, this default service will automatically be selected. The rate for the service will default to the Rate Per Unit, and the number of units will default to 1. For more details, see Setting a default service code and custom rate for a client.

Using multiple service codes

Adding multiple service codes to an appointment 

If a client was seen for multiple services on a single day, you can add multiple service codes to a single appointment. To do this: 

  • Navigate to your Calendar 
  • Select the first service code for an appointment


  • Click + Service to add an additional service code
    • You can add up to 6 service codes per appointment


Note: You can add additional primary service codes as well as add-on codes. For more details, see Using add-on codes

If you add three or more service codes to an appointment, you’ll have the option to rearrange them:


Note: The first service code added for an appointment is considered the original service and can’t be rearranged. If you need to rearrange the position of the first service code, you’ll need to delete and recreate the appointment with the correct order of services.

To delete a service code, click the trash icon next to the code:


The service codes for an appointment will appear on invoices and statements if your Service Description settings are set to populate the Appointment Service and Description. For more information, see Adding appointment descriptions to invoices.

Billing insurance with multiple service codes 

When an appointment has multiple service codes, each one will generate a separate line in box 24a on a claim:


Because of this, each service code will represent an additional appointment on the claim. You can include up to 6 appointments/service codes on one claim.


How do Unit Billing and multiple service codes affect insurance payments? 

A Payment Report (ERA) will generate and attach an insurance payment to the client’s first appointment that matches the date(s) of service on the Payment Report.     

If a service is billed in units or multiple services are added to a single appointment, the payments for all services will attach to the single appointment:


If multiple services are rendered for a client on separate same-day appointments, the insurance payments may attach to the incorrect appointments. When this happens, the insurance payments will have to be manually adjusted. For more details, see Why is my insurance payment only allocating to one service code when there's multiple on the same date of service?

Can I use Unit Billing and multiple service codes on the mobile app?  

Once you set up Unit Billing in the web version of your account, you can use Unit Billing on the mobile app. To select a unit-billed service in the mobile app, you can: 


  • Select a unit-billed service 

When you select a unit-billed service for an appointment in the mobile app, you can adjust the following details: 

  • Units 
    • You can manually enter the number of units, including partial units up to one decimal place 
    • To avoid claim rejections, don’t enter leading zeros (0.5) or trailing zeros (1.0) 
  • Rate per unit
  • Total rate 
    • When this field is adjusted, the Rate per unit field will be disconnected 
      • To reconnect the Rate per unit field, click Reset 
  • Modifiers, if enabled

You can also add multiple service codes by clicking + Add Service

For more information on using the mobile app, see Getting started with the SimplePractice mobile app.

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