Timed Codes: the 8-minute rule

Understand how to calculate time to bill for occupational therapy intervention codes

The 8-minute rule was devised by CMS to determine how to report billable units of timed services. Many, but not all, insurance carriers follow these same guidelines (some use different rounding rules). Use these guidelines for timed services only. If an untimed service is also billed the same day, do not count the time spent on the untimed service toward billable units.

The following chart documents how many minutes must be provided in order to bill the corresponding number of units. Note how 1 billable unit for a timed code must be at least 8 minutes, and it does not increase to a second billable unit until you have at least 8 minutes past the 15-minute mark. If more than one timed CPT code is billed during a calendar day, then the total treatment time determines the number of units billed.