What Is the 8-Minute Rule?
Under Medicare policy for timed outpatient therapy services, billable units are determined by total skilled, one-on-one treatment time. Each unit represents a 15-minute increment, and Medicare allows a unit to be billed when the time for that unit is at least 8 minutes (“more than half” of the 15-minute midpoint).[1][2]
Professional associations (APTA, ASHA) describe the 8-Minute Rule as Medicare’s method and note that some commercial payers may instead apply CPT’s “midpoint” interpretation or other payer-specific policies. Providers should verify the applicable rule with each payer.[3][4]
How to Apply the Rule (Minutes → Units)
The following Medicare time ranges are widely cited in CMS guidance for timed services (15-minute units):[2][5]
| Billable Units | Total Timed Minutes (Same Date of Service) |
|---|---|
| 1 unit | 8–22 minutes |
| 2 units | 23–37 minutes |
| 3 units | 38–52 minutes |
| 4 units | 53–67 minutes |
| 5 units | 68–82 minutes |
| 6 units | 83–97 minutes |
In practice, Medicare sums the minutes of all timed codes for the day, divides by 15 to determine whole units, and then applies the “≥8 minutes remainder” threshold to determine if one additional unit can be billed.[2][6]
Worked Example
Suppose a therapist documents 41 total minutes of skilled, one-on-one treatment (all timed codes) on a single date of service. 41 ÷ 15 = 2 full 15-minute units with 11 minutes remaining. Because the remainder is ≥ 8 minutes, Medicare allows billing 3 units for that date of service.[2][4]
If only 37 minutes were documented, 37 ÷ 15 = 2 full units with 7 minutes remaining; the remainder is < 8 minutes, so the claim would generally be for 2 units.[2]
Multiple Timed Codes on the Same Day
When multiple timed services are furnished on the same date, Medicare sums the minutes across those services to determine the total number of billable units. Allocation of units among the specific CPT codes should be supported by documentation of the minutes spent on each service and payer rules; follow CMS guidance and local carrier instructions as applicable.[2][6]
Important Limitations and Payer Variation
- Medicare vs. CPT midpoint: APTA notes a distinction between Medicare’s 8-Minute Rule and the CPT manual’s “passing the midpoint” standard that some non-Medicare payers may apply. Always check the specific payer policy.[3]
- Timed vs. Untimed codes: The 8-Minute Rule applies to timed codes (15-minute increments). Untimed codes (e.g., evals) are billed differently and aren’t governed by the 8-Minute Rule.[4]
- Documentation must support minutes: Units billed must be backed by defensible documentation of skilled, one-on-one treatment time that meets medical necessity and coverage criteria.[1]
Medicare 8-Minute Rule (Therapy Billing)
The Medicare 8-minute rule determines how many timed CPT units you can bill based on total timed minutes in a single discipline on a single date of service. Add your timed minutes across eligible codes, then map the total to units. For a quick refresher, jump to the minutes-to-units chart or the therapy productivity hub, and pair it with the productivity walkthrough.
Quick unit chart (timed minutes → units)
| Timed minutes | Billable units |
|---|---|
| 8–22 | 1 unit |
| 23–37 | 2 units |
| 38–52 | 3 units |
| 53–67 | 4 units |
| 68–82 | 5 units |
| 83–97 | 6 units |
| 98–112 | 7 units |
| 113–127 | 8 units |
Continue the pattern by adding 15 minutes per additional unit if you support higher totals.
Examples
You provided 30 total timed minutes. 30 minutes maps to 2 units (23–37).
You provided 53 total timed minutes. 53 minutes maps to 4 units (53–67).
You billed two timed codes: 97110 (20 min) + 97530 (18 min) = 38 total timed minutes → 3 units (38–52).
Common questions
- Only timed minutes count toward the total for the 8-minute rule.
- Untimed codes are billed separately and don’t add to the timed total.
- Combine minutes across timed codes within the same discipline for the same date of service.
FAQ
What is the 8-minute rule?
The Medicare 8-minute rule determines how many timed CPT units you can bill based on total timed minutes in a single discipline on a single date of service. Add your timed minutes across eligible codes, then map the total to units.
How many CPT units can I bill?
Medicare’s commonly cited thresholds are: 1 unit for 8–22 minutes, 2 units for 23–37 minutes, 3 units for 38–52 minutes, 4 units for 53–67 minutes, 5 units for 68–82 minutes, and 6 units for 83–97 minutes of total timed treatment on the same date of service.
Does Medicare require the 8-minute rule?
Yes. Medicare applies the 8-minute rule to timed therapy services, but private payers may use different standards (such as CPT’s midpoint policy). Always verify the applicable rule with the payer.
How does this helper decide units?
The helper sums your total timed minutes for the date of service and applies the 8-minute rule thresholds to return the number of billable 15-minute units.
How do I convert minutes into units?
Use the quick chart: 8–22 minutes = 1 unit, 23–37 = 2 units, 38–52 = 3 units, 53–67 = 4 units, 68–82 = 5 units, 83–97 = 6 units, and keep adding 15 minutes per additional unit.
Do I add minutes from multiple timed codes?
Yes. Combine timed minutes across eligible timed codes within the same discipline for the same date of service, then map that total to units using the 8-minute rule.
Informational only — not billing, legal, or compliance advice. Always confirm payer-specific rules and documentation requirements with your compliance team or the payer before submitting claims.
References
-
Centers for Medicare & Medicaid Services (CMS). Outpatient Rehabilitation Therapy Services (MLN Booklet MLN905365): “They must provide more than the 15-minutes midpoint (that is, 8 minutes or more — also known as the 8-minute rule).”
CMS MLN Booklet PDF -
CMS. Medicare Claims Processing Manual, Chapter 5 (Part B). Time-based billing intervals show 1 unit = 8–22 minutes; 2 units = 23–37; 3 units = 38–52; 4 units = 53–67; etc.
CMS Claims Processing Manual -
American Physical Therapy Association (APTA). Coding for Timed Codes — describes differences between Medicare’s 8-Minute Rule and CPT midpoint standard.
APTA Coding for Timed Codes -
American Speech-Language-Hearing Association (ASHA). Timed & Untimed Codes FAQs.
ASHA Timed Codes FAQs -
CMS/Medicare Coverage Database. Coding Guidelines — Therapy and Rehabilitation Services (counting minutes for 15-minute units; threshold table).
CMS LCD Coding Guide -
CMS. Therapy Services — overview of Medicare therapy billing (includes 8-minute policy context and de minimis notes).
CMS Therapy Services