Billing & ClaimsUpdated Dec 18, 2025

The 8-Minute Rule: Complete Guide

Master the CMS 8-minute rule for billing timed physical therapy services, including calculation examples and common mistakes to avoid.

1

Understanding the 8-minute rule

The 8-minute rule is a CMS guideline that determines how many timed units a therapist can bill based on total treatment minutes. You need at least 8 minutes of a timed service to bill 1 unit. The rule applies to timed CPT codes like 97110 (Therapeutic Exercise), 97140 (Manual Therapy), and 97530 (Therapeutic Activities).

2

Calculating billable units

Use the total minutes of all timed services combined: 8-22 minutes = 1 unit, 23-37 minutes = 2 units, 38-52 minutes = 3 units, 53-67 minutes = 4 units. When billing multiple timed codes, allocate units to the services with the most minutes first (the 'rule of eights').

3

How PRACTIS automates this

Morgan automatically tracks treatment time during documentation and calculates billable units using the 8-minute rule. Riley then validates the units during pre-scrub, flagging any discrepancies between documented time and billed units before claim submission.

4

Common mistakes to avoid

Avoid these frequent errors: (1) Billing a unit for less than 8 minutes of service, (2) Counting untimed services (97530) in the timed calculation, (3) Rounding up when total minutes don't meet the threshold, (4) Not documenting start/end times for each service. PRACTIS prevents all of these automatically.

Frequently Asked Questions

Newsletter

Get our weekly PT practice insights

Join 2,400+ practice owners receiving actionable tips on AI automation, billing optimization, and compliance every Thursday.

2,400+ subscribers

No spam, ever. Unsubscribe anytime.

Need help?
Ask our AI assistant about pricing, features, or demos.