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The 8-Minute Rule: How to Avoid Common Mistakes

When it comes to billing and coding medical claims, accuracy is critical. Avoiding claim denials will help you and your practice get paid faster and make sure you’re getting reimbursed for the full amount you deserve. 

But claim accuracy is about more than just your bottom line; it also helps prevent waste and fraud in the healthcare system. Medicare, in particular, has some strict rules for claim filing and reimbursement to avoid abuse and make sure patients get the care they need. 

One of those Medicare regulations is the 8-Minute Rule. But don’t let the simple name deceive you — it’s easy to miscalculate how you bill for a procedure or service under the Medicare 8-Minute Rule. 

Fortunately, we’ve put together this article to help you navigate the numbers and master the intricacies around this important Medicare billing rule.  

What Is the 8-Minute Rule?

Under the 8-Minute Rule, you can bill Medicare for a single “billable unit” of service if it lasts at least eight minutes (up to 22 minutes). After that, you calculate billable units in 15-minute increments.

Medicare rolled out the 8-Minute Rule in April 2000. The rule applies to time-based current procedural terminology (CPT) codes, also known as direct time CPT codes. It doesn’t apply to service-based codes. (We’ll get into the differences between the two in a little bit.)

Because the Medicare 8-Minute Rule applies to direct time CPT codes, it’s most often used by physical therapists and other clinicians who provide in-person, outpatient services. Private practices, skilled nursing facilities and rehabilitation facilities should be familiar with the 8-Minute Rule.

The primary goal of the 8-Minute Rule is to protect patients’ rights — it makes sure they get the care they need and helps avoid over-charging for services.  

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How Does the 8-Minute Rule Work?

Now that you understand the basics of the 8-Minute Billing Rule, let’s dive into some details.

When Does the Rule Apply?

As mentioned above, the 8-Minute Rule only applies to time-based or direct care CPT codes. These codes cover services where the clinician has direct contact with a patient. For example, the rule would apply to a manual therapy session with a physical therapist. 

Here are a few other parameters to keep in mind for the 8-Minute Rule:

  • The clinician must provide the service in person.
  • If the patient receives multiple direct services, you can bill Medicare for the total amount of direct care minutes per discipline.
  • If a single service takes fewer than eight minutes, you cannot bill Medicare for that service.

Service-Based vs. Time-Based CPT Codes

The 8-Minute Billing Rule doesn’t apply to service-based CPT codes. So, what makes these codes different from time-based CPT codes?

Service-based CPT codes typically cover services or procedures where you may not have one-on-one, constant contact with the patient. With a service-based code, you bill for one unit regardless of how long the service or procedure took. 

Some examples of service-based CPT codes in physical therapy or rehabilitation include:

  • Applying a hot or cold ice pack (97010)
  • Traction procedure (97012) 
  • Unattended electrical stimulation (97014)
  • Physical therapy evaluation (97161-97163)

Time-based CPT codes apply to services where you have direct, one-on-one contact with the patient for the whole service or procedure. You bill these services in 15-minute increments (billable units). 

Some examples of time-based CPT codes in physical therapy or rehabilitation include:

  • Manual electrical stimulation (97032)
  • Ultrasound (97035)
  • Therapeutic exercise (97110)
  • Gait training (97116)
  • Manual therapy (97140)
  • Therapeutic activities (97530)

8-Minute Rule Chart and Billable Units

With the 8-Minute Rule, you can bill Medicare for one unit once you hit the eight-minute mark on a time-based service. That first billable unit is good for services that last between eight and 22 minutes. After that, you bill in 15-minute increments. 

For example, a manual therapy session that lasts 10 minutes is one billable unit. The same goes for a therapy session that lasts 20 minutes. A session that lasts 25 minutes is two billable units.

The 8-Minute Rule chart below will help you understand how many units to bill based on the amount of time spent on care. 

8-minute rule chart

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How Do I Calculate Billable Units?

Now that you know how the 8-Minute Rule works, let’s cover how to calculate your billable units. Whether you use an in-house or outsourced billing and coding service, make sure you understand this process as you submit and scrub your claims

When using the 8-Minute Rule for therapy or another direct time procedure, follow these guidelines:

  • Add up all the minutes spent on time-based services for one day. Let’s say it was a total of 47 minutes of care. 
  • Use the 8-Minute Rule chart above or divide that total (47) by 15 to get the number of billable units for the day. In this case, you submit three billable units. 
  • You can include services that take fewer than eight minutes if you also perform other time-based services on the same day. Add the times together and determine how many units you can bill. (For example, a seven-minute ultrasound plus a 20-minute therapy session.) In some cases, you still may end up with only one billable unit. (For example, a seven-minute ultrasound plus a 10-minute therapy session still falls within the one billable unit threshold). 

What Are Mixed Remainders?

As we note in the guidelines above, you can add up all your time-based services to determine your billable units. That’s because Medicare allows you to bill “mixed remainders” together. That means you can combine leftover time spent on different services. 

Here’s an example:

  • You provide manual therapy for 21 minutes, which counts for one billable unit.
  • You provide an ultrasound that takes 19 minutes, which counts for one billable unit.
  • You end up with six remaining minutes for the manual therapy and four leftover minutes for the ultrasound. 
  • When you add up these remainders, you have 10 minutes of combined time-based services. That means you can bill Medicare for one additional unit.
  • You bill for a total of three units. Use the CPT code for the service with the largest remainder (in this case, manual therapy).

8-Minute Rule Examples

Let’s illustrate the 8-Minute Rule with a few examples.

Example 1: Missing the 8-Minute Rule Threshold

You meet with an existing Medicare patient and provide a short manual therapy session that lasts six minutes. You can’t bill Medicare for this session because it doesn’t meet the 8-Minute Rule threshold.

Example 2: Mixing Different Time-Based Services

You meet with one of your regular Medicare patients in your private physical therapy practice. He starts with an ultrasound, which takes seven minutes. After the ultrasound, he undergoes 23 minutes of therapeutic exercise followed by 12 minutes of manual therapy. 

All of these services are time-based. When you add them together, it totals 42 minutes. That means you can submit three billable units to Medicare. 

Example 3: Combining Service- and Time-Based Procedures

It’s time to meet with a new Medicare patient at your physical therapy practice. You start the appointment by evaluating the patient for 25 minutes. To help with your diagnosis and treatment plan, you ask the patient to undergo an ultrasound, which takes nine minutes. 

After the evaluation and ultrasound, you determine the patient would benefit from a few different treatments while she’s at your practice. 

You start with a 23-minute electrical stimulation treatment, which you don’t supervise. While the patient undergoes this treatment, you attend to another patient.

After the electrical stimulation, you provide 21 minutes of therapeutic activity and 12 minutes of manual therapy. Once you complete the manual therapy session, the patient is done for the day and goes home. 

So, how many billable units do you submit to Medicare? 

Initially, it looks like the patient spent 90 minutes receiving treatment, which would work out to six billable units. But when you look closer, it’s not that straightforward — that’s because you provided some service-based and unattended procedures, which you don’t include under the 8-Minute Rule.

Here’s how it breaks down:

  • 25-minute patient evaluation (service-based CPT 97161) = 1 billable unit
  • Nine-minute ultrasound (time-based CPT 97035) = 1 billable unit
  • 23-minute unattended electrical stimulation (service-based CPT 97014) = 1 billable unit
  • 21-minute therapeutic activity session (time-based CPT 97530) = 1 billable unit
  • 12-minute manual therapy session (time-based CPT 97140) = 1 billable unit

The result? You bill five billable units to Medicare, not six.

Mastering Medicare Billing Rules Helps Patients and Your Bottom Line

Although Medicare developed the 8-Minute Rule to protect patients, following it can also improve your revenue cycle process. Sticking to these parameters will make sure you’re not submitting incorrect claims, which can affect your cash flow when Medicare rejects them down the line. 

And since the 8-Minute Rule allows you to combine minutes for time-based services, it helps ensure you get paid in full for the services you provide.

At Gentem, we have a team of revenue cycle specialists who are experts in complex regulations like the 8-Minute Rule. They use their industry knowledge and our proprietary, AI-powered software to find and fix billing and coding problems in your revenue cycle. Ultimately, that means more revenue for your practice.

Want to learn more about our revenue cycle management (RCM) expertise and state-of-the-art RCM software? Book a demo today with one of our medical billing experts.

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