Medicare 8-Minute Rule: A Guide for Physical Therapy

Author: Paul Singh

At first glance, the 8-minute rule may seem fairly straight forward, but there are nuances in this rule that make it more complicated than it appears, especially when billing both time-based and service-based codes on a single patient visit.  Let’s look at the rule and what therapists need to be aware of.

The 8-minute rule, or rule of eights, is there to help therapists determine how many units they can bill to Medicare for the outpatient services they administer on a particular service.  Please note that this rule applies specifically to Medicare Part B services (and insurance companies that have stated they follow Medicare billing guidelines, which includes all federally funded plans, such as Medicare, Medicaid, TriCare and CHAMPUS).   The rule does not apply to Medicare Part A services.

First, let’s examine the difference between time-based and service-based CPT codes.  Service-based, also referred to as untimed, codes are used when performing a physical therapy examination or re-examination, applying hot or cold packs or giving unattended electrical stimulation.  These services allow for only one unit to be billed, no matter how long the treatment takes.

In contrast, time-based, also referred to as direct time, codes can be billed in  multiple units of 15-minute increments.  In other words:

One unit equals 15 minutes of direct therapy

These are for time-based codes where you are providing one-on-one, constant attendance procedures and modalities, like therapeutic exercise or activities, manual therapy, neuromuscular re-education, gait training, ultrasound, iontophoresis or attended electrical stimulation.

CPT Guidelines of Units

In a perfect world, blocks of time for treatment would be divided into 15 minutes of time, but that doesn’t happen.  Treatments come in all time ranges and the 8-minute rule dictates how many units can be billed.  Medicare states that the associated service must be performed for at least 8 minutes to qualify for a billable unit.  Medicare will not reimburse you for seven or fewer minutes.  The total number of skilled, one-on-one time is added up and divided by 15.  If there are eight minutes or more, Medicare allows for an additional unit.  Seven minutes or less, you will not be reimbursed.

Below, you can find a handy chart to help you see how many units you can bill:

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
83-97 minutes 6 units

Things to consider

As with many complicated rules, there are exceptions to the 8-minute rule.  For instance, if you provide skilled treatment for under eight minutes, and the rest of the service is unskilled, you probably won’t be able to bill any direct time for that particular treatment.

Billing Non-Medical Insurances

Like stated previously, Medicare rules do not apply to other insurance policies unless they specifically say so, so the 8-minute rule may not apply.  Private insurance companies usually don’t allow for mixed remainders.  Under the Substantial Portion Methodology (SPM), you cannot bill for any leftover minutes that come from a combination of services, unless one of the individual services total eight minutes.  Before the 8-minute rule, SPM was how services were billed to all patients, including Medicare beneficiaries.  SPM is stilled used with Blue Cross Blue Shield, Aetna, Cigna,  auto insurances (Geico, State Farm, AllState) and Workman’s Comp.

In some cases, SPM may actually allow you to bill for more units than the 8-minute rule does, especially when providing more than one service. If in doubt, it’s best to inquire first before billing.

Need further clarification on the 8-minute rule or have billing questions?  StrataPT is happy to help.  Please contact our friendly team if you want to simplify your billing operations.

Frequently Asked Questions

Who Follows the Medicare 8-Minute Rule?

Any practitioner providing outpatient, in-person services will generally follow the 8-minute rule. The following is a selection of outpatient providers who follow the 8-minute rule:

  • Emergency room
  • Private practices
  • In-home health care (under Part B)
  • Rehabilitation facilities
  • Emergency rooms

How Would I Bill Un-Timed and Timed Codes Together?

For each un-timed code, you would bill one unit. You would bill one unit per 15 minutes spent on that therapy for each timed code. Then, you add these totals together to get your total PT billing units. 

What About Billing for Reassessment Time or Patient Education?

CMS allows you to add time spent teaching a patient how to manage their problem and for time spent re-assessing their condition. This time begins the moment you start interacting with the patient. For example, teaching a patient a new set of home program exercises can be included in Therapeutic Activities unit times or Therapeutic Exercise times. 

Do Other Payers Use the Minute Rule?

Not quite. Unlike Medicaid and similar programs, most providers don’t use the total time spent to determine pt billing units. Instead, they count each therapy as an individual service and allow you to bill accordingly. 

Can Documentation Time Be Included in the Minute Rule?

Yes, but only if the paperwork is done while with the patient. You can’t bill for paperwork done away from the patient. 

Is the Minute Rule in Effect When I Do an Initial Evaluation?

Yes, but only if additional interventions are done on that service date. However, this is an un-timed code and can only be billed for one unit. If timed interventions are done at the initial evaluation, you would use the information above for adding timed and un-timed services. 

How Do I Avoid Problems With the Minute Rule?

The most important thing to do is ensure your documentation supports the intensity and duration of direct one-on-one time spent. Documentation should also clearly match the definitions in the CPT code book for that specific code. 

What’s the Best Way to Avoid Minute Rule Mistakes?

Use an EMR with built-in 8-minute rule functionality for the most accurate billing calculations. For example, StrataEMR will automatically double-check your work and alert you if anything doesn’t add up correctly. 

What Is a Mixed Remainder?

When you divide the time of treatments rendered by 15 and get leftover minutes from multiple services, you have a mixed remainder. You can bill an additional unit of service if the total of those remainders is equal to or greater than 8.

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