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The Medicare 8 Minute Rule: A Comprehensive Guide

Illustration depicting the Medicare 8 Minute Rule

Billing and coding for medical claims can be a tricky business, but getting it right is essential. It ensures you get paid promptly and, equally importantly, helps maintain the integrity of our healthcare system by preventing misuse and fraud. Medicare, in its quest for accuracy, has some specific rules when it comes to filing claims and getting reimbursed. One of these rules is known as the 8-Minute Rule. Despite its straightforward name, understanding and correctly applying the Medicare 8-Minute Rule can be more challenging than it appears. 

In this article, we aim to simplify the complexities of this rule, providing you with the knowledge and tools to use it effectively. Join us as we break down the essential aspects of this crucial Medicare billing guideline.

Understanding the 8 Minute Rule

The 8-Minute Rule, introduced by Medicare in April 2000, is a critical aspect of medical billing. It allows healthcare providers to bill Medicare for a single “billable unit” of service if that service lasts at least eight minutes, up to a maximum of 22 minutes. Once a service exceeds 22 minutes, billable units are calculated in 15-minute increments.

This rule specifically pertains to time-based Current Procedural Terminology (CPT) codes, which are also known as direct time CPT codes. It’s essential to note that the 8-Minute Rule does not apply to service-based codes. We’ll delve into the distinction between these two code types shortly.

The application of the Medicare 8-Minute Rule primarily concerns healthcare professionals who offer in-person, outpatient services. Physical therapists and various clinicians regularly rely on this rule to ensure accurate billing. Additionally, private practices, skilled nursing facilities, and rehabilitation facilities must be well-versed in the 8-Minute Rule’s requirements.

The ultimate objective of the 8-Minute Rule is to safeguard patients’ rights, ensuring they receive the necessary care while preventing excessive charges for healthcare services.

If you are feeling overwhelmed by medical billing, you can contact our team to receive personalized assistance in developing a billing plan that suits your practice.

How the 8-Minute Rule Works

Now that you’ve grasped the fundamental concept of the 8-Minute Billing Rule let’s explore the finer details.

When Does the Rule Apply?

As previously highlighted, the 8-Minute Rule exclusively pertains to time-based or direct care CPT codes, which correspond to services involving direct patient interaction. For example, this rule applies to a manual therapy session with a physical therapist.

Here are some key parameters to consider when applying the 8-Minute Rule:

In-Person Service: The clinician must administer the service in person to trigger the application of the rule.

Cumulative Minutes: If a patient receives multiple direct services from different disciplines, Medicare allows billing for the total direct care minutes per discipline.

Eight-Minute Minimum: For a service to be billable under the 8-Minute Rule, it must last a minimum of eight minutes. Services taking less than eight minutes cannot be billed to Medicare.

Service-Based vs. Time-Based CPT Codes

It’s vital to distinguish between service-based and time-based CPT codes, as the 8-Minute Billing Rule applies exclusively to the latter.

Service-Based CPT Codes:

Service-based CPT codes encompass services or procedures where continuous, one-on-one contact with the patient may not be required. With a service-based code, you bill for one unit, regardless of the duration of the service or procedure. 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:

Time-based CPT codes relate to services that necessitate direct, one-on-one patient interaction throughout the entire service or procedure. These services are billed in 15-minute increments, often referred to as billable units. 

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)

Understanding this differentiation is crucial for healthcare providers to ensure accurate billing and compliance with Medicare regulations. In the following sections, we will delve deeper into the practical application of the 8-Minute Rule, offering you a comprehensive guide to navigate its complexities.

The 8-Minute Rule and Billable Units

The 8-Minute Rule simplifies the process of billing Medicare for time-based services. Here’s how it works:

  • When a time-based service reaches the eight-minute mark, you can bill Medicare for one billable unit.
  • This first billable unit applies to services that last between eight and 22 minutes.
  • For services exceeding 22 minutes, you bill in 15-minute increments, accumulating additional billable units.

Example Scenarios:

  1. Manual Therapy (10 minutes) – One Billable Unit
  • Service duration: 10 minutes
  • Billable units: 1

2. Therapy Session (20 minutes) – One Billable Unit

  • Service duration: 20 minutes
  • Billable units: 1

3. Extended Therapy Session (25 minutes) – Two Billable Units

  • Service duration: 25 minutes
  • First billable unit: 8 to 22 minutes
  • Second billable unit: 23 to 25 minutes

8-Minute Rule Chart

Service Duration
Bilable Units
< 8 Minutes
0 Units
8 to 22 Minutes
1 Units
23 to 37 Minutes
2 Units
38 to 52 Minutes
3 Units
53 to 67 Minutes
4 Units
68 to 82 Minutes
5 Units
83 to 97 Minutes
6 Units
98 to 112 Minutes
7 Units
113 to 127 Minutes
8 Units

How to Calculate Billable Units

Now that you understand how the 8-Minute Rule functions, let’s explore the steps to calculate your billable units. Whether you manage your billing in-house or use an outsourced billing and coding service, it’s essential to grasp this process as you submit and review your claims.

When applying the 8-Minute Rule for therapy or other direct time procedures, follow these straightforward guidelines:

Total Your Minutes: Sum up all the minutes spent on time-based services for a single day. For instance, if the total time spent on care for the day amounts to 47 minutes, take note of this number.

Determine Billable Units: You have two options to calculate your billable units:

  • Refer to the 8-Minute Rule chart provided earlier.
  • Divide the total time (47 minutes in this case) by 15 to obtain the number of billable units. In this example, you’d submit three billable units.

Account for Mixed Remainders: It’s possible to include services that take less than eight minutes, provided you also perform other time-based services on the same day. To calculate billable units in such scenarios, add up the times for each service. 

For instance, if you perform a seven-minute ultrasound and a 20-minute therapy session on the same day, you combine these times to determine your billable units. In some cases, this may still result in only one billable unit. 

For example, combining a seven-minute ultrasound with a 10-minute therapy session falls within the one billable unit threshold.

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Understanding Mixed Remainders

As mentioned in the guidelines above, Medicare allows the aggregation of time-based services to establish billable units. This flexibility extends to “mixed remainders,” enabling you to merge any unused time from different services. Here’s a practical example:

  • You provide manual therapy for 21 minutes, constituting one billable unit.
  • An ultrasound session takes 19 minutes, also counting as one billable unit.
  • You have six minutes left from the manual therapy and four minutes from the ultrasound.

By totaling these remaining minutes, you arrive at a combined 10 minutes of time-based services. Consequently, you can bill Medicare for one additional unit.

In this case, you would bill for a total of three units, selecting the CPT code for the service with the largest remainder (in this example, manual therapy). Understanding these calculations ensures accurate billing in compliance with the 8-Minute Rule.

Billing Guidelines under the 8-Minute Rule

Medicare employs specific billing guidelines when determining the number of billable units for timed services. Understanding these guidelines is essential for accurate billing. 

Here’s a step-by-step breakdown of how it works:

Divide Total Minutes: When Medicare reviews your claim, they calculate the total minutes spent on all timed services for a given day.

Evaluate the Remainder: The division result is assessed. If it leaves at least 8 minutes remaining before reaching the next 15-minute increment, you can bill an additional unit.

Determine Unit Count: If the remainder is less than 8 minutes, you cannot bill an extra unit.

Example Calculation:

Let’s illustrate this with an example involving a physical therapist providing timed services:

  • 15 minutes of therapeutic exercise (97110)
  • 8 minutes of therapeutic activities (97530)
  • 5 minutes of manual therapy (97140)

Total Time: 15 + 8 + 5 = 28 minutes


  • 28 minutes divided by 15 equals 1.86 (one unit, with a remainder).
  • Subtracting 15 from the total leaves 13 minutes as the remainder.

In this example, you can bill for 2 units in total, one for 97110 and one for 97530. However, 97140, performed for only 5 minutes, does not meet the 8-minute rule by itself.

Modifiers in Medicare Billing

In addition to the 8-Minute Rule guidelines, specific modifiers play a vital role in Medicare billing. These modifiers can impact the reimbursement of your claims and are crucial to include when submitting billing information. Here are some common modifiers utilized in Physical Therapy (PT), Occupational Therapy (OT), and Speech-Language Pathology (SLP) billing:

CQ or CO: Designates services performed in whole or in part by a physical or occupational therapy assistant. PTA uses CQ, and OTA uses CO. This modifier applies when a PTA or OTA provides at least 10% of the service. Services provided jointly with the assistant and supervising PT or OT do not require the modifier.

GA: Indicates that the provider has an Advanced Beneficiary Notice (ABN) on file for noncoverage of a provided service that Medicare does not consider medically necessary or reasonable.

GO: Shows that an OT has provided services, typically in an inpatient or outpatient therapy setting.

GN: Indicates that an SLP has provided services, usually in an inpatient or outpatient therapy setting.

GP: Shows that a PT has provided services, typically in an inpatient or outpatient therapy setting.

KX: Indicates that the client has exceeded the Medicare therapy threshold, but services remain medically necessary.

XP: Used when a service is billed separately because it was performed by a separate provider.

22: Employed for increased procedural services when the provider goes beyond what the code typically entails.

52: Utilized when the provider has reduced or eliminated the scope of a billed service at their discretion.

59: Designates the billing of services that are not usually provided together, such as NCCI edit pairs.

95: Indicates services provided through telemedicine (live audio and video).

Understanding and correctly applying these modifiers is essential for ensuring accurate and compliant billing under Medicare guidelines.


The Medicare 8-Minute Rule is a crucial tool that healthcare providers must understand and apply correctly. It not only facilitates fair and accurate billing but also upholds the principle of providing necessary care to patients while preventing excessive charges. As you navigate the complexities of Medicare billing, a solid grasp of the 8-Minute Rule will serve you well, benefiting both your practice and the healthcare system as a whole.

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