Clarice Grote, MS, OTR/L

Clarice Grote, MS, OTR/L

How to Apply the Medicare 8-Minute Rule in OT Billing

When it comes to billing for occupational therapy services, it isn’t always as straightforward as we’d like. Instead of billing per minute or per hour of therapy provided, many payers use units of CPT® Codes to determine reimbursement. But how do we determine how many units to bill? Well, that’s where the Medicare 8-minute rule comes into play.

How to apply the Medicare 8-minute rule in OT Billing

The Medicare 8-minute rule is often a source of confusion for new grads and seasoned practitioners alike. Although it is Medicare’s rule, it is also used by other payers. If how to use the 8-minute rule is confusing to you, you’re not alone. That’s why this week on The Amplify OT Podcast, I am answering a listener question on the Medicare 8-minute rule!

In this episode, I cover:

  • When you will use the 8-minute rule
  • What the 8-minute rule means and how you can apply it in billing.
  • Timed codes vs. untimed codes.
  • Where you might get tripped up in billing and why it can sometimes be referred to as the 15-minute rule.
  • How you can use your time wisely and ensure you are getting paid for the care you are providing.

Billing is such a complex situation, so it is important for you to always go to the source and seek out accurate information. So, let’s dive in!

Social Media Question:

Hello guys, new grad here. No in dept code discussion before. Can you please enlighten me how to bill timed treatment? What I’m doing for now for instance:

30 mins: 20 mins – Gait Training, 10 mins – Therapeutic Activity

20 mins: 15 mins – Gait, 10 mins- Therapeutic Exercise

Am I doing it correctly? How do I apply the 8-minute rule? Thank you in advance!

How to Apply the 8-Minute Rule in OT Billing

The 8-minute rule, sometimes called the 15-minute rule or rule of eights, is utilized by Medicare and other payers to calculate how many units a practitioner can bill under timed codes.  The amount of time that can be used in the 8-minute rule calculation is based on the amount of treatment time provided. 

When calculating how many units to bill, practitioners can only include the time/minutes when they provided covered face-to-face services in their minutes total. Time spent reviewing a chart before seeing the patient, speaking with the nurse, or other services provided that are either unskilled (i.e., changing linens or getting water) or do not involve the patient cannot be included as billable treatment time. 

Timed vs. Untimed Codes

The 8-minute rule is utilized only with timed codes and is not utilized with untimed codes. Timed codes are codes where you can bill multiple units. The number of units you can bill depends on the amount of time spent providing a service that falls within that code’s definition. How many units can you bill? Well, that’s coming up next!

Common timed codes include: 

  • Self care – 97535
  • Therapeutic exercise – 97110
  • Therapeutic activity – 97530
  • Neuromuscular re-education – 97112

Untimed codes are codes where you can only bill one unit regardless of how much time you spent providing the intervention. Examples of untimed codes include evaluation codes or reevaluation codes, orthotics, and some modalities. So, even if you spent 30 minutes or an hour with that patient under the evaluation code, you’re only billing one unit. Meaning you get paid the same amount for that service regardless of if you spent 10 minutes or 100 minutes. AOTA has a great list of common codes used by therapy practitioners that you can view here. (psst… if you want to learn more about timed and untimed codes, check out Mastering OT Policy & Medicare)

Where is the 8-minute rule used?

The 8-minute rule is primarily used in outpatient or anywhere you’re billing Medicare Part B. Billing in units is considered a Fee-for-Service model or volume-based payment model. Generally, the rule isn’t used for Medicare Part A since most reimbursement models under Part A don’t reimburse for therapy based on minutes. However, you may still document using units for productivity purposes or because other payers may require the 8-minute rule for services typically covered under Medicare Part A like SNF stays or home health services.

Why is it called the 8-Minute rule?

To bill one unit of therapy, you have to provide a minimum of 8 minutes of one-on-one, face-to-face therapy. Additionally, those 8 minutes have to be provided under one code. Meaning you can’t provide 4 minutes under a self-care code and 4 minutes under a ther-ex code and bill for it. In that scenario, you just wouldn’t be paid for your time. But, if you provided 8 minutes of therapy under a self-care code, you could bill one unit.

The Math

Now, here’s where things get confusing…

You would think if something’s called the “8-minute rule”, it would mean that for 8 minutes of treatment, you could bill 1 unit, and then at 16 minutes of treatment, you can bill 2. But that’s not how it works – because life can’t be that easy in healthcare.

So, this is where the rule starts to be called the “15-minute rule” because there is a 15-minute gap between when you can bill 1 unit and when you can bill 2. This is because if you look at the definition of CPT® Codes, the code description includes 15-minute of treatment. Below is a quick chart showing how many units you can bill based on how many minutes of care are provided. (Note: You can bill more than 4 units in a session – just follow the same pattern)


Now, you likely have a chart like this in your electronic medical record or have seen in school (I also have it on Amplify OT’s OT Billing Guide). Personally, I have always found it easier just to memorize the chart. But… I’m also math impaired.

If you happen to find yourself without this handy chart, you can also use an equation to calculate your units. To calculate your units, you divide the total amount of treatment time by 15. If you have 8 minutes left over, you can bill one additional unit. If you have less than 8 minutes left over, you cannot bill an additional unit. 

For example, if you provided 30 minutes of treatment time and divided it by 15, that equals 2 without any remainder. Therefore, you can build 2 units. As you can see, this also aligns with the chart because 30 minutes falls between the threshold of 23 to 37 minutes of total treatment time, which is 2 units of therapy.

What if we have 40 minutes of treatment time? The math’s not as easy. So if you divide 40 by 15, you’re still going to get 2, but there’s going to be a remainder. In this case, there are 10 minutes left over, so you would be able to bill 3 units.

Now, you may find yourself saying, wait a minute… If I provide 23 minutes of care, I get paid the same amount as when I provide 37 minutes of care – so… I’m just not getting paid for those 14 minutes of care??? And the answer is… kind of?

Maximizing Reimbursement Under the 8-Minute Rule

As you may have noticed, since the 8-minute rule involves a range, there is essentially a certain amount of time you don’t seem to get paid for. Now, the argument would be that it all averages out and that technically, the code is based on 15 minutes being provided, so sometimes you’re being paid more than you should, and sometimes you’re being paid less.

However, if you’ve utilized the 8-minute rule for billing, you’ve probably had a boss remind you to keep a close eye on the clock and track when you might only be a few minutes short of the next threshold. Since units are also often used for productivity, if you aren’t keeping close track of your time, you could be underbilling or not getting recognized for the actual time you are providing care to the patient.

For example, let’s say you have 22 billable minutes in a session. In this case, you can only bill one unit. If you’re looking at it from a dollar perspective, you are essentially not getting paid for 14 minutes of your time. Now, let’s say you do that 7 times in one day, all of a sudden, you haven’t been paid for 98 minutes of care that day. What if, for at least a few of those visits, you spent a few more minutes with the patient so you could reach the two unit threshold? You would receive more appropriate reimbursement for your time, and it’d probably also help your productivity.

An important note here: You should NEVER round up your minutes in order to meet that next threshold. Billing for the care you didn’t provide violates numerous laws and puts your license at risk. Instead, if you keep an eye on your time, you can make a more informed decision. Sometimes, more care can be provided that is beneficial to the patient. Some examples of quick interventions that provide value to the patient and also help you and your company include:

  • Providing additional education
  • Reviewing a home exercise program one more time
  • Reviewing your goals

That being said, if it isn’t appropriate to continue a session, then don’t. This is where things balance out. Over-providing therapy is also a potential violation of the law and is harmful to the patient. So, as with everything, there is a delicate balance that requires you to utilize your clinical judgment.

When is the 8-Minute rule not used?

Some insurers may use something called Substantial Portion Methodology (SPM). SPM does not follow the 8-minute rule and can allow clinicians to bill a unit per code as long as they provided a minimum of 8 minutes under that code. (8 minutes is a substantial portion of 15 minutes). This is a whole other topic for a future podcast and article, so if you’re interested in learning more about that, then I definitely recommend you check out the Mastering OT Policy & Medicare course.

Additionally, the 8-minute rule does not necessarily apply to most therapy services reimbursed under Medicare Part A since most Medicare Part A models are value-based payment models which focus more on the quality of care vs. quantity of care. But, as this article identified earlier, you may report units in your documentation in those scenarios.

Answering the Question! How to Bill in the Scenario Provided

Here’s the question again as a refresher:

Hello guys, new grad here. No in dept code discussion before. Can you please enlighten me how to bill timed treatment? What I’m doing for now for instance:

30 mins: 20 mins – Gait Training, 10 mins – Therapeutic Activity

20 mins: 15 mins – Gait, 10 mins- Therapeutic Exercise

Am I doing it correctly? How do I apply the 8-minute rule? Thank you in advance!

When looking at the example of 25 vs. 30 minutes, both will fall between 23 minutes and 37 minutes. Meaning no matter what, this person can only bill 2 units of therapy. Those two units can be split into two different codes, or they can go under one code. The clinician should pick whichever code is most appropriate for the service provided. 

Remember, you can only calculate units based on the total treatment time. So, if you had 31 minutes of total treatment time, you can’t put 23 minutes under self-care and 8 minutes under ther-ex and try to bill 3 units. 31 minutes would still only be two total units, according to the 8-minute rule. Technically, you could report it that way, but you wouldn’t be paid for one of those codes. However, I would encourage clinicians to avoid this scenario to help reduce any potential overbilling or claim denials.

Report Minutes as Accurately as Possible

In this example, they used round numbers. However, clinicians should strive to report minutes as accurately as possible under each code versus always using round numbers. 

Now, this doesn’t mean you have to use a stopwatch to track how much time was provided under each code but make your best estimate. You also want to make sure that your documentation supports the amount of time and the codes you billed. So, if you billed 10 minutes of ther-ex, your documentation should support 10 minutes of ther-ex. 

AOTA has some great resources on billing, which I’ve listed below, and as always, make sure to go to the source! Your billing and documentation are really important both for legal and reimbursement reasons and because this information can also inform reimbursement models of the future. 

If you have any questions like this one, feel free to send them my way, and I might just answer them in my next podcast and article! 


Want to learn more about the 8-minute rule and other billing requirements? Check out Mastering OT Policy and Medicare – a comprehensive course on Medicare and reimbursement, especially for OT practitioners and students! Are you ready to become your own best resource? Check it out HERE!

Clarice standing in a light room smiling wearing black pants and a light green puff sleeve shirt

hi there,

I’m  Clarice

Occupational therapist & medicare specialist helping practitioners understand policy, engage in advocacy, and own their value!

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