Understanding the Medicare 8 Minute Rule

If you bill Medicare in your private practice, you already know there’s a lot to consider to make sure you’re billing clients accurately. The 8 minute rule, sometimes called the Medicare Rule of 8, is one of these factors. 

Here, we’ll break down what the 8 minute rule is, how 8 minute rule therapy billing works, and what to watch out for when submitting your claims. 

What Is the 8 Minute Rule?

The 8 minute rule allows therapists, usually rehabilitation therapists, to accurately determine the number of units they can bill for specific timed services. The 8 minute rule generally applies to Medicare billing, although some private insurers also use it as well. If you’re not sure if your private insurer requires 8 minute rule billing, check in your payer contract or reach out to their customer service team to double check. 

The 8 minute rule only applies to certain services—specifically, skilled services that are billed with time-based codes, as opposed to service-based codes. There are a couple different qualifiers that make a service a “skilled” service, but a main one is that the services, observations, or treatment plan require the involvement of technical or professional personnel to meet the client’s needs. Some examples of skilled services are therapeutic exercises or activities that require the supervision of a qualified provider, like a PT or an OT, as well as range of motion exercise and the services of an SLP when necessary for the restoration of function in speech or hearing. 

In addition to the skilled services requirement, the 8 minute rule is also only required for time-based services, which we’ll dig into below. 

Defining Time-Based vs. Service-Based CPT Codes

The Medicare 8 minute rule is based on time-based service codes, but not all CPT© codes are time-based. Certain modalities and evaluations are service-based, meaning that you bill the same amount for that service regardless of how long you administered it. 

Some examples of time-based codes are: 

• 97110 – therapeutic exercises 
• 97140 – manual therapy 
• 97035 – ultrasound
• 97530 – therapeutic services 
• 97542 – Wheelchair management/propulsion training 

These codes would be subject to 8 minute rule billing requirements, which we’ll walk through below. On the other hand, you may be offering services that are billed with service-based codes, such as: 

• 92506 – Speech/hearing evaluation 
• 95833 – Manual muscle testing 
• 97001/97002 – physical therapy evaluation/re-evaluation 
• 97003/97004 – occupational therapy evaluation/re-evaluation 

As you can see, depending on your speciality, the kinds of clients you see, and the kinds of treatments you’re using, you may or may not actually need to bill with the 8 minute rule in therapy. Sometimes this distinction will even show up within the same session, which can make 8 minute rule billing seem even more overwhelming—but there’s a way to walk through it to make sure you’re providing your clients the care they need and billing for it correctly. 

If you’re unsure of whether the service you’re providing and the associated code is time-based or service-based, double check before you bill it. You can confirm your codes through your state or national professional organization, or through the CMS website. 

How 8 Minute Rule Billing Works

To understand how 8 minute rule billing works, let’s first look at the CMS definition: “For any single timed CPT code in the same day measured in 15 minute units, providers bill a single 15 minute unit for treatment greater than or equal to 8 minutes through 22 minutes. If the duration of a single modality or procedure in a day is greater than or equal to 23 minutes through and including 37 minutes, then 2 units should be billed.” 

This can sound confusing, so let’s break it down. For each time-based service you’re offering, make sure you time how long you provide that service, and then convert to billable units accordingly. In order to bill one unit of a timed CPT code, you must provide the associated modality for at least 8 minutes. So, Medicare adds up the total minutes of skilled therapy services provided and divides the resulting amount by 15. If there are eight minutes or more left over after that division, you can bill for another unit, but if seven minutes or fewer remain, you can’t bill another unit, and you basically have to drop that remainder. 

Here’s an example: if you perform manual therapy (a time-based service) for 15 minutes and then ultrasound (another time-based service) for eight minutes, you can bill two direct units. 

You can use this chart to help you convert time to  billable units: 

Time Delivered	Billable Units
Less than 8 minutes	0 units
8 – 22 minutes	1 unit
23-37 minutes	2 units
38-52 minutes	3 units
53-67 minutes	4 units
68-82 minutes	5 units
83-97 minutes	6 units

Mixed Remainders

Inevitably, you’ll have time in your session that doesn’t fall neatly into eight or 15 minute blocks. What do you do with those leftover minutes? They’re sometimes referred to as mixed remainders, and there is a way to account for them within the context of 8 minute rule billing. 

For instance, let’s say you have a remainder of minutes in your session that was five minutes of manual therapy and three minutes of ultrasound. Both of those services are time-based and so eligible to be billed under the 8 minute rule. Per Medicare rules, as long as the sum of your remainders is eight minutes or more, you should bill for the individual service with the biggest time total—even if that total is less than eight minutes on its own. In our example, you would bill for one additional unit of manual therapy. 

To navigate mixed remainders, double check if the services you offered in those minutes would be subject to 8 minute rule billing requirements. If they’re not—i.e., if they are service-based codes—you’re not able to bill another unit for that service, even if it meets the time requirement. 

8 Minute Rule Billing Examples

To help clarify all of these 8 minute billing rules, here’s some examples of a few sessions and how you might bill for them. 

8 Minute Rule Billing Example 1: 

You provide 15 minutes of therapeutic activity and 10 minutes of therapeutic exercise, so your total treatment minutes is 25. 

Since you surpassed 22 minutes, you’re able to bill for two units under the 8 minute rule. 

8 Minute Rule Billing Example 2: 

You provide 10 minutes of therapeutic activity, 10 minutes of manual therapy, and 10 minutes of cold pack. Your total timed treatment minutes is 20 minutes. 

The reason the total treatment minutes is 20 rather than 30 is because of the cold pack treatment. In this scenario, the cold pack treatment is considered a service-based treatment, so you would only bill one unit for it regardless of how long you used it for. So, accounting for the service-based treatment, you have 20 minutes of time-based treatments, which means you have only one billable unit. Since therapeutic activity and manual therapy are both time-based and eligible for 8 minute rule billing, it’s up to you to decide which code you want to bill. You might consider billing the code that has a higher reimbursement rate, so make sure you check what the rates are for your different codes before submitting the bill.

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