- What is the 8-Minute Rule in Medical Billing
- How the 8-Minute Rule Operates (and What It Means for Your Clinic)
- The Timed vs. Untimed CPT Codes That Are the Basis for the 8-Minute Rule
- The Standard Error in Therapy Billing
- CMS vs. AMA 8-Minute Rule Differences and Billing Implications
- Why Understanding This Difference Matters
One of the most significant, yet confusing, Medicare billing concepts in therapy is known as the 8-Minute Rule. It shows you the way outpatient therapists charge via time-based CPT codes under Medicare Part B. This is a rule for all types of therapists, including physical therapists, occupational therapists, and speech-language pathologists who work as suppliers to deliver Medicare services.
The 8 Minute Rule is more than just understanding timed services, reimbursement benchmarks and documentation requirements to make sure your billing is not only compliant but also effective. In this article, we’ll break it all down so your clinic can bill better, stay compliant, and enhance Medicare reimbursement velocity.
What is the 8-Minute Rule in Medical Billing
Put in its simplest terms, the 8-Minute Rule is used for documentation and billing of timed (coded) therapeutic service visits or treatment time; this regulation helps to decide how many billable units a therapist can charge per patient visit based on the length of therapeutic service that is being provided. Medicare enacted it to ensure that therapy billing is fair and accurate.
Such a rule allows you to charge only a timed CPT code if the service was provided for at least eight minutes. Anything less is considered non-billable. The rule makes sure that therapists are paid for the time they really spend treating patients—and no more, no less.
It applies mostly to Medicare Part B claims and to many commercial payers as well. This is especially important in physical therapy (PT), occupational therapy (OT), and speech therapy (SLP) practices. For instance, if a therapist does a timed procedure for 22 minutes, you can charge 1 unit for each full fifteen-minute period and another unit if the remaining time exceeds 8 minutes.
Here’s the basic logic simplified:
| 0–7 minutes | Not billable |
| 8–22 minutes | 1 unit |
| 23–37 minute | 2 units |
| 38–52 minutes | 3 units |
and so on.
Therefore, next time the 8-Minute Rule comes up in therapy billing discussions, keep these hardworking principles in mind: it’s all about transferring treatment time into proper and compliant billable units.
How the 8-Minute Rule Operates (and What It Means for Your Clinic)
Now that you’re clear on what the 8-Minute Rule actually is, let’s tackle this thing with some real-life examples of the 8-Minute Rule in therapy billing situations—because practically speaking, we find that’s where many therapists run into confusion.
Example 1: One-Time Service (Easy Case)
For instance, suppose a physical therapist does manual treatment (CPT 97140) for 20 minutes. The 8-Minute Rule says … any time between 8 and 22 minutes = 1 billable unit. Ok, so the therapist can charge 1 unit for CPT 97140.
Example 2: Combo of Timed Services (Greater Prevalence in PT/OT)
Imagine a therapy session that includes:
• 15 minutes of therapeutic exercise (97110)
• 12 minutes of neuromuscular re-education (97112)
• 10 minutes of manual therapy (97140)
| CPT Code | Minutes Spent | Billable Units | Notes |
|---|---|---|---|
| 97110 | 15 | 1 | 1 unit |
| 97112 | 12 | Part of combined 22 min | |
| 97140 | 10 | Part of combined 22 min | |
| Combined: 97112 + 97140. | 22 | 1 | 1 more unit (whichever code took longer) |
Example 3: When the 8-Minute Rule and Total Time Don’t Align
A therapist performs:
• 7 minutes of exercise (97110)
• 7 minutes of manual therapy (97140)
That’s 14 minutes total, but each code individually is below 8 minutes—so none are billable separately. However, when two or more timed services total at least 15 minutes, you can bill one unit for the code that took the longest time. So here, bill 1 unit of 97110.
Why It Matters
Getting this wrong can result in claim denials, underbilling, or compliance issues. That’s why Pro-Medsole RCM ensures every minute is accurately tracked and billed—so your PT, OT, and SLP claims get paid fast and correctly.
The Timed vs. Untimed CPT Codes That Are the Basis for the 8-Minute Rule
Before properly implementing the 8-Minute Rule, you must first master timed and untimed CPT codes. This is a big reason why therapy billing errors occur with physical therapy, occupational therapy, or speech therapy claims.
Timed CPT Codes
Timed codes are applicable where a therapist provides hands-on treatment for a period of time. These codes are also based on 15-minute intervals and calculated on the basis of direct face-to-face patient time.
| CPT Code | Service Description | Billable Time | Example Setting |
| 97110 | Therapeutic exercise | Per 15 minutes | Private Practices |
| 97112 | Neuromuscular re-education | Per 15 minutes | Rehabilitation Facilities |
| 97140 | Manual therapy | Per 15 minutes | Hospital Outpatient Departments |
| 97535 | Self-care/home management training | Per 15 minutes | Home Therapy Services |
Untimed CPT Codes
Untimed codes, by contrast, are billed once for the session—regardless of how long it lasts. They’re not subject to the 8-Minute Rule because they are paid at a fixed rate per service.
Examples of Untimed CPT Codes:
• Physical therapy evaluation (97161-3.11-2)
• Group therapy (97150)
• Unattended electrical stimulation (97014)
So, timed services are based on minutes, but untimed services depend on what you did, not how long it took.
The Standard Error in Therapy Billing
There are also numerous clinics that throw a blend of timed and untimed codes into a single claim without making it easy to identify which one. This leads to non-compliance and may even initiate CMS audit activity.
For example, let’s say a therapist codes 10 minutes of manual therapy (97140) and PT evaluation (97161) under the same session; the manual therapy is bound by the 8-Minute Rule—but not the evaluation.
With Pro-Medsole RCM, our billing experts meticulously break out service and time-based codes so your claims are well in line with Medicare’s billing and reimbursement guidelines—you stay audit-ready AND financially secure.
CMS vs. AMA 8-Minute Rule Differences and Billing Implications
While many therapists and billing teams get confused with the Medicare 8-Minute Rule and the AMA’s Rule of Eights, both are designed to standardize services provided with timed codes. Minor distinctions can affect reimbursement policies and claims processing for physical therapy, occupational therapy, and speech therapy unit treatments.
Knowing those nuances results in proper billing and increases your revenue, all while being compliant. (For a broader professional discussion, see AAPC’s AMA vs Medicare debate).
CMS 8-Minute Rule
The CMS 8-Minute Rule applies mainly to Medicare Part B and dictates how timed services (i.e., therapeutic exercise, manual therapy, and neuromuscular re-education) should be coded. It’s one 15-minute unit for every 8 minutes of direct patient management that you can bill.
Direct Therapy Time → Billable Units:
| Time (minutes) | Billable Units |
|---|---|
| 0–7 | Not billable |
| 8–22 | 1 |
| 23–37 | 2 |
| 38–52 | 3 |
| 53–67 | 4 |
AMA Rule of Eights
The AMA’s Rule of Eights is slightly different and often referenced by commercial payers or non-Medicare insurance. It uses a rounding system for timed CPT codes. Any remainder under 8 minutes may be rounded down, and 8 or more minutes can be billed as a full 15-minute unit. Unlike CMS, the AMA focuses on general compliance with CPT codes rather than strictly Medicare billing thresholds.
Why Understanding This Difference Matters
Not knowing the distinction can lead to denials, claim rejections, and revenue loss. For instance, a group therapy session billed with incorrect rounding may get partially paid or rejected. Similarly, documentation errors related to time tracking can flag audits by CMS or commercial payers.
At Pro-Medsole RCM, our experts monitor billing modifiers (e.g., GP, GO, GN, CQ, GA), ensure proper record audits, and apply both CMS and AMA rules accurately. This means your practice, whether a private practice, rehabilitation facility, hospital outpatient department, or home therapy service, can focus on patient care while we safeguard revenue.
Frequently Asked Questions
Q1. How does the 8-minute rule work?
Therapy rules have permitted therapists to bill one unit of a time-based CPT if eight minutes of skilled, in-person treatment was given during the visit.
Q2. What insurances follow the 8-minute rule?
Medicare and the majority of commercial insurance companies follow the CMS guidance bill under the 8-minute rule when billing for time-based therapy.
Q3. Does Blue Cross follow the 8-minute rule?
Yes, many BCBS Blue Cross Blue Shield have adopted the 8-minute rule but this may not be true for states and individual plan policies
Q4. What insurances follow the 8-minute rule?
Medicare, Medicaid (most states), and some commercial payers such as BCBS, Aetna or Cigna billing of outpatient therapy will adhere to the 8-minute rule.