Medicare 8-Minute Rule - Physical Therapy Billing Units

Physical therapists bill you on timed-based codes or service-based codes. Time-based codes are complex, which is why Medicare implemented the 8-minute rule as a unit measurement for payment.
Edward Neeman
Published on
August 30, 2018
Updated on
January 22, 2024

If you find yourself in the unfortunate position where you need physical therapy, you may worry about the costs. The good news is if you are a Medicare beneficiary of your Medicare Part B coverage includes any physical and occupational therapy deemed “medically necessary”. This includes the vital therapies required following a stroke, fall, or any number of debilitating illnesses.

In fact, annual caps on Medicare coverage for physical therapy, payment caps that have generally been exempted at periodic intervals by Congress, have been permanently removed as of 2018.

Under the new rules, once your bills reach a certain amount each year your physical therapist notes on future claims that the continuing therapy is medically necessary. With that simple step, your treatment can continue. However, you may have noticed your physical therapist paying careful attention to the length of your sessions. If you are curious why they are rushing you out of your weekly appointment, or distracted by the clock, it may relate to what is known in the industry as the Medicare 8-minute rule.

What Is Medicare’s 8-Minute Rule?

The Medicare 8-minute rule is a guideline from the Centers for Medicare & Medicaid Services (CMS) that providers must adhere to when billing Medicare for your physical therapy unit. Physical therapy appointments that fall under this guideline are time-based. Per CMS, your physical therapist must provide direct treatment for at least 8-minutes to bill Medicare for time-based physical therapy.

What Services Does The Rule Apply To?

CMS rules on physical therapy distinguish between two different types of physical therapy treatment you can receive service-based treatments and time-based treatments.

A service-based physical therapy unit does not have to meet the 8-minute rule and may include evaluations, reevaluations, unattended electrical stimulation, or the application of hot and cold packs to your injury.

Time-based treatments include things like exercise, ultrasounds, electrical stimulation, iontophoresis, and a variety of physical therapeutic activities. These treatments all must meet the physical therapy 8-minute rule.

How The 8-Minute Rule Works

Under Medicare’s physical therapy 8-minute rule, CMS determines how many physical therapy units are billable by calculating the total minutes you spent doing one-to-one, time-based therapy on a single day. That total is divided by fifteen to determine the number of billable units. If there are over 8-minutes leftover an additional unit can be billed. For any remainder less than 8-minutes, Medicare will pay nothing.

Physical Therapy Billing Unit Chart

Below is a quick guide for calculating the billable physical therapy units under the Medicare 8-minute rule. The length, in minutes, of a time-based appointment, will determine the physical therapy unit, or units, that are billable to Medicare.

  • 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 minutes = 6 units

What Happens With Mixed Remainders?

A physical therapy unit becomes even more complex when mixed remainders are thrown into the equation. At one physical therapy appointment, you may undergo multiple treatments. If there are leftover minutes from several different time-based treatments, these are known as mixed remainders.

Alone, these minutes may not meet the Medicare 8-minute rule but do when added together. For example, if you have 4 minutes of therapeutic exercise followed by 5 minutes of electrical stimulation, together they total over 8-minutes of time-based treatment. CMS allows your provider to bill one additional unit to whichever treatment was longer, in this example electrical stimulation.

Using Calculators To Avoid Mistakes

The calculations are all somewhat complex, but fortunately for you, your physical therapy provider will take care of the math. Calculators are necessary to determine an accurate physical therapy unit calculation for time-based treatments. Even more accurate are the electronic medical records most providers now use. These EMRs come with built-in algorithms that are programmed to fit Medicare guidelines for the physical therapy 8-minute rule.

Related News Articles

Start Comparing Plans Now

Use our online Medicare quoting tool and gain access to the best plans in your area