8 Minute Rule for Therapy Reimbursement

In the world of therapy practice, time is measured in billable units, which determine how treatment will be reimbursed. The 8-minute rule helps therapists keep track of billable units, and it’s easy to use.  

What is the 8-minute rule?

According to the CMS (Centers for Medicare and Medicaid Services), billable units are 15 minutes long. That means Medicare will reimburse a treatment based on how many of these 15-minute increments or billable units it entailed. 

Here it is in writing from their website:

“For any single timed CPT code in the same day measured in 15-minute units, providers bill a single 15-minute unit for treatment greater than or equal to 8 minutes.”

It’s technically a “15-minute rule” according to CMS, but we therapists refer to it as the 8-minute rule because that’s when reimbursement kicks in. 

What is the 8 minute rule?

The 8 minute rule is a Medicare guideline for determining how many billable units may be charged in rehabilitation based on time spent with the patient. Billable units are based on 15 minute increments, once the initial 8 minutes have been met, which is how the name “8 minute rule” developed.

So why is it called the 8 minute rule?

Sometimes a treatment doesn’t fit nice and neatly into 15-minute intervals. Because of that, CMS will allow just 8 minutes to count as one billable unit. 

Within a 15-minute block of time, you cross the half-way point at 8 minutes…well, technically, 7 minutes and 30 seconds.

Think of 8 minutes as the tipping point. Once you’ve crossed 8 minutes, the 15 minute block counts as a unit!

By spending at least 8 minutes with your patient, you’ll “satisfy” the majority of the 15-minute block of time in order to bill for one unit.   

Technically it’s the “8 Minutes Plus 15 Rule”….

But this wiggle room goes the other way too. If your treatment extends past 15 minutes but does not reach 23 minutes, then it’s still just one billable unit.

CMS qualifies the 15-minute rule as any treatment “greater than or equal to 8 minutes through and including 22 minutes.” So if your treatment was 20 minutes, you only have one unit to bill.

This works incrementally as you accumulate units: 

“If the duration of a single modality or procedure in a day is greater than or equal to 23 minutes through and including 37 minutes, then 2 units should be billed.”

The handy chart below will help you visualize the 8-minute rule: 

8 Minute Rule Chart

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

Good to Know: The total timed minutes of time-based CPT codes determines how many units you can bill Medicare. Suppose you performed 3 different treatments, but only spent 5 minutes on each one. In that case, your total timed minutes is 15. Despite the three different treatments, 15 minutes equals only 1 unit, so you’ll have to choose which CPT code to bill. 

Timed vs Untimed Codes

Remember: the 8-minute rule only counts for “timed” minutes, regardless of the total treatment time (which may include “untimed” minutes such as hot/cold packs). So which CPT codes are “timed” and which are “untimed”?

Untimed CPT Codes:

• Evaluation, Re-evaluation 97161, 97162, 97163
• Cold/Hot Packs 97010
• Electric Stim (Unattended) 97014

Timed CPT Codes:

• Therapeutic Exercise – 97110
• Manual Therapy – 97140
• Neuromuscular Re-ed – 97112
• Therapeutic Activity – 97530
• Gait Training – 97116
• Ultrasound – 97035
• Iontophoresis – 97033*
• Electric Stim (Manual)  97032

*Yes, iontophoresis is considered a timed CPT code even though you’re usually not standing next to the patient while the ionto is running.

8 Minute Rule Examples

Let’s review a few 8-minute rule examples. Remember, only timed minutes count toward the 8-minute rule, which  is why they are bolded below.

Example 1 Treatment:

• 15 min Therapeutic exercise
• 10 min Manual Therapy

Total Treatment Time: 25 min

Untimed Minutes: 0

Timed Minutes: 25 

Billable Units: 2 total units (1 Ther ex, 1 Manual)

Example 2 Treatment:

• 10 min Therapeutic Exercise
• 10 min Manual Therapy
• 10 min Hot Pack

Total Treatment Time: 30 minutes

Untimed minutes: 10

Timed Minutes: 20 

Billable Units: 1 (Therapist may choose which CPT code)

In this example, the therapist did not cross the 23-minute threshold for 2 units, so they can only bill 1 unit. As for which unit (e.g., ther ex or manual therapy) it’s up to the therapist – most will choose ther ex for the higher reimbursement rate. That’s perfectly ethical since both treatments were 10 minutes. However, if the therapist spent 11 minutes on manual therapy but 9 minutes on ther ex, they should choose to bill manual therapy. 

Example 3 Treatment

• 16 min Therapeutic Exercise
• 22 min Neuromuscular Re-ed
•  7 min Therapeutic Activity

Total Treatment Time: 45 minutes

Untimed Minutes: 0

Timed Minutes: 45 

Billable Units: 3 (2 NM, 1 Ther ex)

In this example, the therapist clearly performed 1 unit of ther ex. But they’re also billing for 2 units of neuromuscular re-education, which might be confusing since 22 minutes does not cross the 23-minute threshold for 2 units. However, billing is based ultimately on total timed minutes – 45 in this case, and equivalent to 3 billable units. Those 7 minutes spent on therapeutic activity still count toward timed minutes because Therapeutic Activity is a timed code. 

Therefore, the therapist can ethically bill 2 units of neuromuscular re-ed because neuro re-ed was a larger focus of the treatment in terms of minutes spent.   

Want to Save Time on Documentation?

If you’re interested in becoming more efficient with documentation and saving 30 to 60 minutes a day, check out the Therapy Documentation Templates. These templates include time-saving examples and documentation phrases for all kinds of treatments.

Questions on the 8-Minute Rule?

If you have any questions about the Medicare 8-minute rule, put them in the comments and we’ll try to answer them!