The combined offense level is determined by taking the offense level applicable to the Group with the highest offense level and increasing that offense level by the amount indicated in the following table:
| Number of Units |
Increase in Offense Level |
| 1 |
none |
| 1 1/2 |
add 1 level |
| 2 |
add 2 levels |
| 2 1/2 – 3 |
add 3 levels |
| 3 1/2 – 5 |
add 4 levels |
| More than 5 |
add 5 levels. |
In determining the number of Units for purposes of this section:
(a) Count as one Unit the Group with the highest offense level. Count one additional Unit for each Group that is equally serious or from 1 to 4 levels less serious.
(b) Count as one-half Unit any Group that is 5 to 8 levels less serious than the Group with the highest offense level.
(c) Disregard any Group that is 9 or more levels less serious than the Group with the highest offense level. Such Groups will not increase the applicable offense level but may provide a reason for sentencing at the higher end of the sentencing range for the applicable offense level.
Application Notes:
1. Application of the rules in §3D1.2 and §3D1.3 may produce a single Group of Closely Related Counts. In such cases, the combined offense level is the level corresponding to the Group determined in accordance with §3D1.3.
2. The procedure for calculating the combined offense level when there is more than one Group of Closely Related Counts is as follows: First, identify the offense level applicable to the most serious Group; assign it one Unit. Next, determine the number of Units that the remaining Groups represent. Finally, increase the offense level for the most serious Group by the number of levels indicated in the table corresponding to the total number of Units.
Background: When Groups are of roughly comparable seriousness, each Group will represent one Unit. When the most serious Group carries an offense level substantially higher than that applicable to the other Groups, however, counting the lesser Groups fully for purposes of the table could add excessive punishment, possibly even more than those offenses would carry if prosecuted separately. To avoid this anomalous result and produce declining marginal punishment, Groups 9 or more levels less serious than the most serious Group should not be counted for purposes of the table, and that Groups 5 to 8 levels less serious should be treated as equal to one-half of a Group. Thus, if the most serious Group is at offense level 15 and if two other Groups are at level 10, there would be a total of two Units for purposes of the table (one plus one-half plus one-half) and the combined offense level would be 17. Inasmuch as the maximum increase provided in the guideline is 5 levels, departure would be warranted in the unusual case where the additional offenses resulted in a total of significantly more than 5 Units.
In unusual circumstances, the approach adopted in this section could produce adjustments for the additional counts that are inadequate or excessive. If there are several groups and the most serious offense is considerably more serious than all of the others, there will be no increase in the offense level resulting from the additional counts. Ordinarily, the court will have latitude to impose added punishment by sentencing toward the upper end of the range authorized for the most serious offense. Situations in which there will be inadequate scope for ensuring appropriate additional punishment for the additional crimes are likely to be unusual and can be handled by departure from the guidelines. Conversely, it is possible that if there are several minor offenses that are not grouped together, application of the rules in this part could result in an excessive increase in the sentence range. Again, such situations should be infrequent and can be handled through departure. An alternative method for ensuring more precise adjustments would have been to determine the appropriate offense level adjustment through a more complicated mathematical formula; that approach was not adopted because of its complexity.