Nov. 1 Guideline Change Adds Fentanyl-Related Substances

On November 1, 2026, unless Congress acts first, the main federal drug guideline, USSG §2D1.1, gets a new line for "fentanyl-related substances." These drugs will be scored the same way as fentanyl analogues. A defendant can rebut that rule by showing the substance blocks fentanyl's effect or is much weaker than fentanyl. The change is Amendment 3 in the 2026 amendments the Sentencing Commission sent to Congress on April 30, 2026.

Why the Commission made this change

A "fentanyl-related substance" is a drug that is built like fentanyl but has small chemical changes. The term is defined by chemical structure in 21 U.S.C. § 812.

Congress passed the HALT Fentanyl Act (Pub. L. 119-26) in July 2025. It put fentanyl-related substances on Schedule I for good. It also set the same mandatory minimums for them as for fentanyl analogues (21 U.S.C. § 841(b)(1)):

• 10 years for 100 grams or more of a mixture containing a fentanyl-related substance
• 5 years for 10 grams or more

The guidelines did not list these drugs by name. The Commission says its data showed that, before the Act, courts sentenced most of these cases as if they involved fentanyl analogues. The amendment writes that practice into the guideline.

What changes on November 1

The Drug Quantity Table. The table in §2D1.1(c) sets a starting offense level by drug type and amount. The amendment adds a fentanyl-related substance line at every level, using the same amounts as fentanyl analogues. For example:

• 9 kilograms or more starts at level 38
• At least 10 grams but less than 40 grams starts at level 24
• Less than 1 gram starts at level 12

For mixed-drug cases, 1 gram of a fentanyl-related substance converts to 10 kilograms of "converted drug weight," the same as a fentanyl analogue.

A way to rebut the presumption. The analogue-level score is a presumption, not an automatic rule. A new note to the table lets the defendant show that the substance either:

• blocks, reduces or counteracts the effect of fentanyl or a fentanyl analogue, or
• is significantly less potent than fentanyl.

If the defendant shows either one, the court scores the drug using the most closely related controlled substance in the guideline instead. The Commission added this because the legal definition is based on chemical structure alone, so it can cover substances that act very differently.

The marketing enhancement. §2D1.1 already adds levels when someone misrepresents or markets fentanyl or a fentanyl analogue as another drug, or as a legitimately made drug. The amendment extends that enhancement to fentanyl-related substances. It applies in those cases only if the court is using the fentanyl-related substance line of the table, and not the rebuttal route.

Phone and communication cases. The amendment also updates a note to §2D1.6, the guideline for using a phone or other communication facility in a drug crime. The note now lists fentanyl-related substances among the drugs for which the Drug Quantity Table sets a minimum offense level of 12.

Who it affects

This matters most for people sentenced on or after November 1, 2026, in cases involving a fentanyl-related substance. The court generally uses the Guidelines Manual in effect on the day of sentencing (USSG §1B1.11). If the new manual would produce a higher range than the one in effect when the offense happened, the court must use the older one (Peugh v. United States, 569 U.S. 530 (2013)).

The rebuttal route turns on lab evidence. In a case involving one of these substances, the defense should know exactly which compound the lab found and what is known about how it acts. A guideline range is a starting point. The judge must still weigh the factors in 18 U.S.C. § 3553(a) before choosing a sentence. Mandatory minimums are covered in our guide to mandatory minimum sentences.

Facing a federal sentence? Book a consultation and tell us what happened. We’ll listen, tell you whether we can help, and explain what comes next.