The 851 Enhancement

Last Updated on: 10th December 2025, 04:03 pm

The 851 Enhancement: How Prior Drug Felonies Double Your Federal Sentence

The 851 enhancement exists for thousands of defendants but is only filed against a fraction of them. In fiscal year 2016, exactly 6,153 defendants were eligible for the enhancement based on prior drug felonies. Only 757 had the enhancement filed against them – just 12.3%. And of those, only 243 actually served enhanced sentences at the end. That’s 3.9% of eligible defendants. The enhancement isn’t about punishing prior convictions. It’s about leverage.

A federal judge called the 851 enhancement “the shocking, dirty little secret of federal sentencing.” He wasn’t exaggerating. Prosecutors file the enhancement early, threaten to double or triple mandatory minimums, then withdraw it in exchange for guilty pleas and cooperation. The defendants who actually serve enhanced sentences aren’t necessarily those with the worst records. They’re those who refused to take the deal.

Understanding how 21 U.S.C. § 851 actually works – and understanding that the filing decision matters more than your eligibility – is essential for anyone facing federal drug charges with prior convictions. Your prior felonies make you eligible. The prosecutor’s filing decision determines whether those priors actually double your sentence.

The 12.3% Reality: Who Actually Gets Enhanced

Here’s the statistical truth about the 851 enhancement that changes everything.

In fiscal year 2016, the U.S. Sentencing Commission found that 6,153 federal drug trafficking defendants were eligible for § 851 enhancement based on prior convictions. These defendants had qualifying priors. They met the criteria. The enhancement could have been applied.

Only 757 had the enhancement filed against them. That’s 12.3% of eligible defendants. The other 87.7% had qualifying priors but never faced the enhancement because prosecutors chose not to file it.

Of those 757 defendants with enhancements filed, only 583 still had the enhancement in place by sentencing. The rest had it withdrawn. And of those 583, only 243 defendants actually remained subject to enhanced mandatory minimums at final sentencing.

That’s 3.9% of eligible defendants. Out of 6,153 people who could have been enhanced, 243 were. The enhancement doesn’t exist to punish prior convictions uniformly. It exists as a tool prosecutors use selectively.

How the Enhancement Actually Works: The Mechanics

Heres how the 851 enhancement operates and why the procedure matters so much.

Under 21 U.S.C. § 851, a defendant cannot be sentenced to an increased punishment based on prior convictions unless a federal prosecutor files an “information” with the court. This information is a document that identifies the prior convictions the government intends to use for enhancement. Without this filing, the enhancement dosent apply – even if you have a dozen qualifying priors.

The prosecutor must file this information BEFORE trial or BEFORE you enter a guilty plea. This deadline is absolute. If the prosecutor misses it, they cant enhance your sentence later. This creates a strategic window – the filing decision must happen early, which means it becomes part of plea negotiations rather then a sentencing outcome.

Once filed, the enhancement doubles your mandatory minimums:

• A 5-year mandatory becomes 10 years
• A 10-year mandatory becomes 15-20 years
• Two or more priors could mean 25 years to life

The enhancement dosent add years – it multiplies them.

The defendant has the right to challenge the enhancement at a hearing. The government must prove the prior convictions qualify. But challenging dosent happen in most cases becuase most defendants dont go to trial – they take deals to avoid the enhanced minimums the prosecutor is threatening.

The Filing Decision That Determines Everything

OK so heres the system revelation that explains why 851 works the way it does. The prosecutor decides wheather to file. Thats it. Same defendant, same drugs, same priors – the prosecutor’s decision determines whether you’re facing 7 years or 19 years.

In fiscal year 2016:

• Defendants who had 851 filed against them received an average sentence of 147 months
• Eligible defendants who DIDN’T have 851 filed against them received an average sentence of 86 months

That’s a 61-month difference – over 5 years – based entirely on the prosecutor’s filing decision.

And for defendants who remained subject to enhanced minimums at sentencing? Average sentence of 225 months. Thats nearly 19 years. Compared to 86 months for eligible defendants without the filing.

The difference between 7 years and 19 years isnt based on what you did. Its based on what the prosecutor decided to file. Same priors. Same drugs. Same defendant. Completely different outcome based on a document the prosecutor chose to file or not file.

This is why mandatory minimums actually increase prosecutorial power rather than limiting judicial discretion.The prosecutor decides the enhancement. The judge executes whatever sentence the statute requires.

The Geographic Lottery

Heres the uncomfortable truth about how 851 enhancements are distributed across the country. Where you get prosecuted matters more then what you did.

The Sentencing Commission found massive geographic disparities in 851 filings:

• In 5 federal districts, the enhancement was sought against more then 50% of eligible defendants
• In 19 federal districts, the enhancement was sought against ZERO eligible defendants

Same law. Same eligibility criteria. Completly different outcomes based on location.

This isnt supposed to happen. Federal law is federal law. But prosecutors in different districts have different policies, different priorities, different approaches. A defendant in one district faces near-certain enhancement. A defendant in another district with identical circumstances never has it filed.

Theres no legitimate justification for this disparity. The defendants are similarly situated. The crimes are the same. The priors are the same. The only difference is which U.S. Attorney’s Office handles the case. And that difference determines decades of your life.

What Qualifies as a Prior Conviction

Here’s what counts for 851 enhancement purposes – and what doesn’t.

Before the First Step Act, the enhancement applied to anyone with a prior “felony drug offense.” This was broad. Almost any drug conviction could qualify if it was punishable by more than one year.

After the First Step Act of 2018, the standard became “serious drug felony.” This requires three things:

1. The prior offense must have been punishable by 10 or more years
2. You must have actually served more than 12 months
3. You must have been released within 15 years of the current offense

That 15-year recency window is an escape hatch many defendants dont know about. If you were released from your prior sentence more then 15 years before your current offense, that prior dosent count for 851 purposes. A conviction from 2000 with release in 2003 cant be used to enhance an offense in 2020. But you have to know to argue it.

State convictions count. A state drug felony can qualify as a federal prior for 851 purposes. That old state case you thought was behind you can double your federal mandatory minimum. Many defendants are blindsided by state priors being used in federal enhancements.

The First Step Act Changes

The First Step Act of 2018 changed several aspects of 851 enhancements. Understanding what changed matters for your case.

Before First Step Act:

• Prior “felony drug offense” qualified
• One prior: 10-year minimum became 20 years
• Two or more priors: Life imprisonment possible

After First Step Act:

• Prior “serious drug felony” required (10+ year offense, 12+ months served, released within 15 years)
• One prior: Enhanced minimum reduced to 15 years
• Two or more priors: Enhanced minimum capped at 25 years (not life)

The First Step Act also added “serious violent felony” as a qualifying prior – not just drug offenses. But it narrowed what counts as a qualifying drug prior through the 15-year window and 12-month service requirement.

If you were sentenced BEFORE December 21, 2018, the old harsher rules apply. The First Step Act isnt retroactive for 851 purposes in most cases. Defendants sentenced under the old rules are stuck with those sentences unless other relief applies.

The 225 vs 86 Month Reality

Here’s what the numbers actually mean for real defendants.

• Defendants eligible for 851 who DIDN’T have it filed received average sentences of 86 months – about 7 years
• Defendants who remained subject to enhanced minimums at sentencing received average sentences of 225 months – nearly 19 years

That’s a 139-month difference. Over 11.5 years. Same eligibility. Same qualifying priors. Different filing decisions produced different outcomes measured in decades.

With 87% of federal sentences served (no parole):

• 86 months means approximately 6.2 years of actual incarceration
• 225 months means approximately 16.3 years of actual incarceration

The difference between getting out at 45 and getting out at 55. The difference between your kids being in elementary school and your kids being adults.

These aren’t theoretical numbers. There real defendants serving real time. The enhancement filing decision – a document a prosecutor chooses to file or not file – determines whether someone serves 6 years or 16 years.

The Timeline That Matters

Understanding when 851 decisions get made helps you understand were your leverage exists.

The prosecutor must file the 851 information before trial or before you enter a guilty plea. This is a hard deadline. If they miss it, they cant enhance your sentence later – even if you have ten qualifying priors.

This deadline creates a strategic window. In most cases, the 851 filing decision happens during plea negotiations. The prosecutor threatens to file. You negotiate. Either you reach a deal and the enhancement isn’t filed (or is filed then withdrawn), or negotiations fail, and the enhancement gets filed before your plea or trial.

Think about what this means. The 851 decision isn’t made at sentencing based on your case merits. Its made during negotiations based on what the prosecutor wants from you. Guilty plea? Cooperation against others? Information about larger operations? The enhancement exists to pressure these concessions.

Once 851 is filed, it stays on the table unless the prosecutor withdraws it. The prosecutor can withdraw at any time before sentencing – they control the withdrawal decision just like they controlled the filing decision. This is how 757 filings became 243 enhanced sentences. Prosecutors withdrew enhancements as part of deals struck after filing.

The sentencing hearing is where it all resolves. If 851 remains in place at sentencing, the judge determines your final sentence using the enhanced mandatory minimums. But by that point, most of the decisions that mattered happened months earlier during negotiations.

Common Mistakes Defendants Make With 851

Defendants make predictable mistakes when facing 851 enhancement threats.

Mistake 1: Assuming the enhancement will definitely be filed. Only 12.3% of eligible defendants have 851 filed against them. The prosecutor might threaten it and never file. Understanding that the enhancement isnt automatic gives you negotiating room.

Mistake 2: Not checking whether priors actually qualify. The First Step Act changed what counts as a qualifying prior. Many defendants have priors that DONT qualify – but they never check. Does your prior meet the 10-year offense threshold? Did you serve 12+ months? Were you released within 15 years? Each requirement can eliminate a prior.

Mistake 3: Ignoring the 15-year window. If you were released from your prior sentence more then 15 years before the current offense, that prior cant be used for 851 purposes. But defendants dont know to argue this. There sentenced with enhancements that shouldnt have applied becuase nobody raised the timing issue.

Mistake 4: Treating 851 as punishment rather then leverage. Defendants see the enhancement threat as punishment for there record. But thats not how prosecutors use it. Its leverage for guilty pleas and cooperation. Understanding this changes how you negotiate.

Mistake 5: Not recognizing the geographic disparity. If your in a district that files 851 against most eligible defendants, your situation is different then a district that rarely files. Understanding your district’s patterns helps you assess realistic outcomes.

Mistake 6: Failing to challenge the prior conviction. Even if you think your prior qualifies, challenges can succeed. Procedural defects, constitutional problems with the prior case, or errors in the governments calculations can eliminate priors. But challenges require action – they dont happen automatically.

How Prosecutors Use 851 as Leverage

Heres the system revelation that explains everything. The 851 enhancement isnt primarily about punishing prior convictions. Its about leverage.

Prosecutors file 851 early – before trial or plea. This puts the enhanced minimum on the table. The defendant now faces double the sentence if they go to trial and lose. The prosecutor then offers to withdraw the enhancement in exchange for a guilty plea, cooperation, or other concessions.

This explains why 757 defendants had 851 filed but only 243 remained enhanced at sentencing. The rest had enhancements withdrawn as part of deals. The filing wasnt punishment – it was a bargaining chip.

Attorney General Eric Holder explicitly addressed this in a 2014 memo. He instructed prosecutors that “whether a defendant is pleading guilty is not one of the factors enumerated in the charging policy” and that “an 851 enhancement should not be used in plea negotiation for the sole or predominant purpose of inducing the defendant to plead guilty.”

But the practice continues. The geographic disparities prove it. Districts that file 851 against 50%+ of eligible defendants are using it differently then districts that file against 0%. And the withdrawal patterns prove it – enhancements are filed then withdrawn in most cases, suggesting there purpose was negotiation leverage rather then punishment.

Challenging the Enhancement

If 851 is filed against you, you have options to challenge it.

Challenge the prior conviction itself. Maybe the prior offense wasnt actualy punishable by 10+ years. Maybe you didnt serve 12+ months. Maybe the 15-year window has expired. Each of these challenges can eliminate a qualifying prior.

Challenge procedural defects. If the government filed the 851 information late, after trial began or after you pled guilty, the enhancement may be invalid. Deadline violations can invalidate the enhancement entirely.

Challenge constitutional defects in the prior. If you didnt have counsel in the prior case (and didnt properly waive counsel), the conviction might be unconstitutional and unusable. If you werent properly advised of consequences, thats another avenue.

Negotiate withdrawal. Since most 851 filings are withdrawn before sentencing anyway, negotiating the withdrawal is often more realistic then winning a legal challenge. The prosecutor filed it as leverage – your leverage is what you can offer in return.

At any challenge hearing, the government bears the burden of proving the prior convictions qualify by preponderance of evidence. They must produce certified copies of judgments, prison records, and evidence of the conviction itself. You have the right to contest all of it.

The Racial Disparities Nobody Discusses

Heres an uncomfortable truth the system dosent like to acknowledge. The 851 enhancement has racially disparate impact.

In fiscal year 2016:

• Black defendants comprised 42.2% of drug trafficking defendants eligible for 851 enhancement
• But Black defendants constituted 51.2% of defendants against whom 851 was actualy filed
• The enhancement was filed against 14.9% of eligible Black defendants versus 11.4% of eligible White defendants

This disparity exists at every stage. Black defendants are more likely to be eligible (due to prior conviction disparities). Black defendants are more likely to have 851 filed when eligible. Black defendants are more likely to remain subject to enhancement at sentencing.

The Sentencing Commission documented these disparities without explaining them. Geographic variation might account for some – if more Black defendants are prosecuted in districts that file more 851 enhancements, disparities compound. But the pattern raises serious questions about how prosecutorial discretion operates in practice.

The Questions You Should Be Asking

“What is the 851 enhancement” is the wrong question. You now know what it is – a statutory mechanism that doubles mandatory minimums based on prior convictions, filed at prosecutor discretion against a small fraction of eligible defendants.

The right questions are:

• Am I eligible for 851 enhancement based on qualifying priors?
• Has the prosecutor filed or threatened to file 851?
• Do my priors actualy qualify under the First Step Act standards?
• Has the 15-year recency window expired for any priors?
• What can I offer to negotiate withdrawal of the enhancement?

These questions lead to realistic strategy. The general enhancement question leads to confusion about why similarly situated defendants face wildly different outcomes.

12.3% filing rate. 3.9% enhanced at sentencing. 225 months with enhancement versus 86 months without. The 851 enhancement isnt automatic justice – its prosecutorial discretion converted into decades of prison. Understanding that reality is the first step toward navigating it.

The defendants serving enhanced sentences arent necessarily those who committed worse crimes or had worse records. There often the defendants who refused deals, who insisted on trial, who didnt provide cooperation. The enhancement exists as leverage. The prosecutor decides whether to use it. And that decision – not your priors, not your conduct – determines wheather your serving 7 years or 19 years for the same offense.