8-Minute Rule of Medicare: Your Ultimate Guide to PT Units Billing

Physical therapy has never been focused on the procedures of rehabilitation billing and practices regulated by the Centers for Medicare and Medicaid Services (CMS). At this time, nearly 44 million providers and practices are enrolled under CMS and by the end of 2030, the population of practices currently studying will take the numbers up to 79 million. These numbers are assumed to be the double number of enrollees as of 2000.

This increase in enrollments will eventually decide how PT units billing for physical therapy practices will be impacted. In addition, Healthcare Financing Administration (HCFA) announced the use of the 8-minute rule in the billing of Medicare beneficiaries from April 1, 2000, according to Transmittal 747 for outpatient physical therapy services.

The announcement was made in December 1999 and since then, it is applied even to the patient for therapeutic services who approach doctors directly. PT units billing was redefined according to the number of times the services are performed in the entire treatment process.

Therefore, with time, Transmittal 747 was brought to be known as the 8-Minute Rule. However, there are scenarios where this 8-minute rule or Transmittal 747 is applied differently based on the situation.

Later in the article, you will find out how to apply PT unit billing codes for different scenarios and why.

Insurance companies that follow the 8-minute rule from Medicare

PT unit Billing Scenarios for Medicare Part B patients

The following scenarios are assumed for a beneficiary of Medicare part B;

Scenario #1: Combination of multiple CPT codes

Three weeks ago, a Medicare part B beneficiary visited your clinic following a cerebral vascular accident treatment. You begin your treatment with;

  • 10-mints of pre-gait activities
  • 10-mints of postural and balance exercises
  • 15-mints of transfer treatment
  • 25-mints of strengthening and ROM – range of motion exercises

PT codes for billing for scenario #1

According to the 8-minute rule, the efficient way of billing to Medicare would be one of the following multiple codes;

  • One PT unit of 97112 (used for neuromuscular reeducation), two units of 97110 (used for therapeutic exercises), and one unit of 97116 (used for gait training)
  • On PT unit of 97110, two units of 97116, and one unit of 97112
  • Two PT units of 97110 and 97116

Coding Justification;

The total treatment time that a provider spent for the treatment in reference with to all CPT codes is 60 minutes. According to the Medicare 8-minute rule, the following chart explains how you can bill for every unit of time spent;

8 – 22 minutes1 unit
23 – 37 minutes2 units
38 – 52 minutes3 units
53 – 67 minutes4 units
68 – 82 minutes5 units
83 minutes6 units

During scenario 1, the treatment session provided pre-gait training of 10 minutes and 15 minutes of transfer training, which means a total of 1 minute of focused training was provided. In addition, ROM and strengthening exercises took 15 more minutes while treating the patient while 10 minutes focused on sitting and balancing exercises. As these exercises come under all of the codes mentioned above so you can use any three of them covering the exercises and the services you provided. Plus, don’t forget to pack your coding selection with the documentation.

Scenario # 2: Wound care and Whirlpool

Another scenario in our list follows the treatment of open wounds due to arterial insufficiency treatment. The treatment includes;

  • 10 minutes of total surface sharp debridement or 15 square cm.
  • 15 minutes’ gait training
  • 20 minutes’ whirlpool
  • 25 minutes’ complexity evaluation

PT codes for billing for scenario #2

According to the 8-minute rule, the correct billing for the wound in question would be;

  • 1 unit of 97597 (used for removal of devitalized tissues of wounds up to 20 centimeters)
  • 1 unit of 97166 (used for moderate complexity or PT evaluation)
  • 1 unit of 97116 for gait training

Coding justification

From the above-mentioned table, the treatment that consumed a total of 15 minutes would be billed against a single CPT code. This is because the only therapeutic service that is provided is gait training. Therefore, the only billable unit used to determine the CPT code is 97116. This is because 97597 and 97001 are untimed codes, this means that you can use them only once.

PS – When you use code 97597, it includes the charges for whirlpool. So whenever you claim for whirlpool reimbursement, you will not use CPT 97022 for whirlpool, as it will duplicate the treatment and it will increase the chance of claim rejection.

Scenario # 3: Example 1 – Mixed Remainders

A Medicare part B beneficiary comes to you for treatment after a left knee replacement surgery he had three weeks ago. The treatment involves;

  • 15 mint treadmills warm-up
  • 20 minutes of balancing exercises with equipment
  • 35 minutes of strengthening and ROM exercises

PT codes for billing for scenario #3

For Medicare 8-minute rule, you can bill on either two ways;

  • 2 units of 97112- and 2-unit’s id 97110
  • 1 unit of 97112 (neuromuscular reeducation) and 3 units of 97110 (therapeutic exercise)

Coding Justification

For this Medicare beneficiary, the total amount of time used is 55 minutes. Therefore, the billable codes for CPT would be four codes. However, you cannot use the treadmill time for billing as Medicare sees them as a non-skilled therapy where the physician’s efforts are nor identified, hence, they will not reimburse you for the claim. As balancing exercise took 15 minutes and Rom with the strengthening exercise took 30 minutes, you would bill two units from 97110- and one unit from 97112. With this, you are left with a 5-minute reminder for 97110 and 97112 for the treatment provided. Here, a biller needs to decide the code that suits the best and determine the true value for the remaining 10 minutes for rendered services. Whatever a biller decides to bill, attach the supporting document with the claim.

Insurance companies that follow the 8-minute rule from Medicare

PT unit Billing Scenarios for Medicare Part B patients

Now when you know how to use 8-minute rule codes in different scenarios, it’s high time to figure out the insurance companies that follow the 8-minute rule and accept claims for the same. In some cases, insurance companies use the Substantial Portion Methodology – SPM for accepting claims. However, for physical therapy billing the 8-minute rule is standard as it is a time-based service.

Sources that require PT providers to use the 8-minute rule for claim submission include;

  • Medicaid
  • Medicare
  • Medicare Advantage Program
    • Pyramid life
    • Aetna Advantage plan
    • Humana advantage plan
    • Medicare Plus Blue
  • Other Federal Payers
    • Blue Cross for Federal employees
    • OWCP- Office of Workers’ Compensation Program regulated by ACS
    • Champus (Veterans)
    • Tricare (Armed services)

Time and Untimed CPT codes

There are codes that can be used once in the claim form and are service-based codes are called untimed codes that you have seen in scenario # 2. These codes, however, are not limited to being used for the one-on-one contract with the provider.

  • G0283 Electrical Stimulation, Medicare Non-Wound (Unattended)
  • electrical stimulation (unattended) (97014)
  • physical therapy evaluation (97161, 97162, or 97163) or re-evaluation (97164)
  • hot/cold packs (97010)

On the other hand, timed codes are must be based on the provide one on one direct contract and are variable with the increment of 15 minutes in the provided service.

A single code of CPT code 97110 defines any therapeutic exercise that is given within 15 minutes of the therapy session. Depending on the condition or scenario, the same CPT code 97110 can be used by another provider who has provided the therapeutic service for the same service for 10 minutes. The key difference occurs when the codes used for different lengths are used in the claims.

As of untimed codes, which can be levied up to 15 minutes, timed codes can be varied up to 8 minutes for one-unit billable service according to the 8-minute rule as described above.


Whenever a physical therapy provider submits claims to any federal payer, it is crucial to understand and follow the 8-minute therapy rule. The above scenarios will help you identify 8-minute rules for claims and use correct CPT codes for timed and untimed codes that will minimize the chances of claim rejection. However, if you are unsure about the billing codes used and the ones that are upgraded in the ICD-10 or ICD-11 codes list, always hire a clearinghouse who works to identify billing errors and mend the billing mistakes that often billers make in their claims.

Also, outsourcing your revenue management to a medical billing company like Clinicast will help you through your complex therapeutic billing needs with perfection. Contact today to lessen your billing and claiming burden and focus more on providing treatments and caring for your patients in personal or multiple healthcare facilities.