8-Minute Rule: Determining the Number of Billable Units

Introduction to the 8-Minute Rule

Some CPT and HCPCS codes are billed based on the amount of time spent with the patient. When these timed, also known as time-based, codes are reported on the billing claim, the number of minutes is rounded to the nearest 15-minute increment using the 8-minute rule.

Free 8 Minute Rule Downloadable PDF

Timed and Untimed Procedure Codes

Some procedure codes are timed while others are untimed, also known as service-based. For example, an annual well visit is an untimed procedure, so it does not matter how much time was spent directly with the patient when filing the claim. 

With timed codes, the amount of direct patient contact time needs to be reported. Most timed procedure codes are billed based on a 15-minute increment, known as a unit. So, if a service is provided for 15 minutes, 1 unit is reported, if a service is provided for 30 minutes, 2 units are reported, and so on and so forth.

Rounding Time Spent Using the 8-Minute Rule

Unless otherwise specified, the amount of time spent is allowed to be rounded to the nearest 15-minute increment. Since half of 15 minutes is 7.5, the provider has to spend at least 8 minutes with the patient in order to bill one unit. So, if a service is performed for 38 minutes, for example, it can be billed for 3 units. If the direct patient care is 7 minutes or less, no billable units can be reported.

8 minute rule chart showing the number of minutes for the number of units from 0 to 8

Reporting the Number of Billable Units on the Claim

When billing on a CMS1500 form, the number of units is entered into field 24G labeled “DAYS OR UNITS.” If the CPT or HCPCS code is an untimed code, a “1” should be entered as the number of units.

Nutrition-Related Codes that Utilize the 8-Minute Rule

Dietitians use the 8-minute rule regularly when billing. The MNT codes used for individual counseling, 97802 and 97803, are 15 minute increments, so they use the 8-minute rule. HCPCS code G0270 uses it as well. 

chart that shows what dietitian cpt codes use the 8 minute rule

Nutrition-Related Codes that Do Not Use the 8-Minute Rule

However, it is important to note that not all codes dietitians may use are time-based. A somewhat notorious example of this is HCPCS code S9470. Some dietitians assume it is a time-based code that can be billed for multiple units for an appointment, but the Academy of Nutrition and Dietetics (AND) has commented saying it should only be billed for 1 unit unless otherwise stated by the insurance payer. 

There are also many billing codes that are based on 30 minute increments. Some of these include:

  • 97804
  • G0271
  • G0108
  • G0109

Most of these codes can be rounded to the nearest 30 minute increment, except for G0108 and G0109, as the Centers for Medicare & Medicaid Services (CMS) has never explicitly stated whether or not rounding is allowed.

There are also some procedures that have multiple codes for different time lengths. For example, CPT code 99401 is for “preventive medicine counseling…approximately 15 minutes.” If 30 minutes were spent with the patient for this service, instead of billing two units of 99401, one unit of CPT code 99402 would be used, as it is for “approximately 30 minutes” of the service. 

Medicare 8-Minute Rule Vs AMA Rule of Eights

It is important to note that the 8-Minute Rule is specifically a Medicare rule. When it comes to medical coding and billing, both CMS and the American Medical Association (AMA) have their own rules and regulations. This can make things confusing, as sometimes the rules are the same, while other times they are different.

The Medicare 8-minute rule is very similar, but has some slight nuanced differences, compared to the AMA rules of eights. Both rules state that the amount of time spent with the patient can be rounded to the nearest unit. With the 8-minute rule, “mixed remainders” are allowed to be added together, while the rule of eights does not allow this.

This mixed remainders concept is when multiple procedures are being provided at the same appointment and there are left over minutes from some of the procedures. Medicare says these minutes can be added up together, while the AMA says they cannot. This is important for some provider types, such as physical therapists, to understand.

However, it would be rare for a dietitian to bill for multiple time-based procedure codes in one visit, so mixed remainders would not apply.

If you are a provider type that needs to be concerned about mixed remainders, it is important to clarify with each payer and plan which rule they follow. 

Wrapping Up the 8-Minute Rule

Dietitians need to understand what procedure codes they are billing for and if they are timed versus untimed. For timed procedures, only the time spent directly with the patient can be counted. This time spent can be rounded to the nearest billable unit.

You can download a free 8-minute rule chart from the Dietitian Direction Well Resourced Dietitian Store. Post it where you do your billing for a quick reference!


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