There is one federal supermax prison in the United States (ADX Florence in Colorado), but dozens of state-level supermax or supermax-style units , and there is no single, universally agreed current count for all of them.

Quick Scoop: Key Facts

  • The only federal supermax is the United States Penitentiary, Administrative Maximum Facility (USP ADX Florence) in Florence, Colorado.
  • Many states operate their own supermax or “supermax‑level” facilities/units , but different agencies define “supermax” differently, so totals vary.
  • By the late 1990s, there were at least 57 supermax facilities across 30–34 states , though some have since closed or been downgraded.
  • Modern estimates usually describe the number as “dozens of facilities or units” rather than a precise nationwide figure, because states reclassify, repurpose, or close units over time.

What “Supermax” Actually Means

Supermax prisons are facilities (or dedicated units inside larger prisons) designed for the most dangerous, disruptive, or high‑profile prisoners , usually featuring near‑total isolation and extremely tight security.

Typical features include:

  • 23+ hours per day in a single cell, very limited human contact.
  • Extensive use of solitary confinement , heavy surveillance, and controlled movement.
  • A design goal of preventing escape and limiting violence inside the prison system.

Because some states build stand‑alone supermax prisons and others use supermax‑style wings inside regular maximum‑security prisons, counting them is tricky.

Federal vs. State Supermax Prisons

Here’s a simple breakdown:

html

<table>
  <tr>
    <th>Level</th>
    <th>Approximate number</th>
    <th>Examples</th>
  </tr>
  <tr>
    <td>Federal</td>
    <td>1 federal supermax facility</td>
    <td>USP ADX Florence (Colorado)</td>
  </tr>
  <tr>
    <td>State</td>
    <td>Dozens of state supermax prisons or units</td>
    <td>Pelican Bay (CA), Red Onion (VA), others designated as Level 6 / supermax</td>
  </tr>
  <tr>
    <td>Historical snapshot</td>
    <td>At least 57 supermax facilities in 30–34 states by 1999</td>
    <td>Many later downsized, repurposed, or reclassified</td>
  </tr>
</table>

Sources describe one federal supermax but emphasize that many states run their own supermax‑level facilities , without a stable, exact nationwide count.

Why You See Different Numbers Online

If you dig through recent news, academic pieces, or forum discussions, you’ll notice numbers that don’t match. That’s because:

  • Definitions differ – Some counts only include stand‑alone supermax prisons; others include supermax housing units in regular maximum‑security prisons.
  • Facilities change status – Prisons get downgraded, closed, or repurposed , which shifts them out of the “supermax” category.
  • Data isn’t centrally tracked – The federal system is clear (one ADX), but states publish their own classifications and don’t always label things “supermax” in a consistent way.

A common pattern in professional and media sources today is to say there is one federal supermax plus numerous state supermax facilities/units , rather than giving a single fixed national number.

Forum-Style Perspective & Recent Context

On forums and in recent commentary about “how many supermax prisons are in the US” , people often argue over whether to count:

  1. Just ADX Florence – for “pure” federal supermax.
  2. ADX + named state supermax prisons – like Pelican Bay (California), Red Onion (Virginia), or other “Level 6” style units.
  1. All supermax‑like isolation units – which can dramatically increase the count because many maximum‑security prisons have such wings.

Human‑rights and criminal‑justice discussions also highlight that tens of thousands of prisoners have been held in supermax‑type conditions nationwide, even though the number of actual supermax facilities is far smaller.

Direct Answer in One Line

If you need a one‑sentence takeaway:
There is 1 federal supermax prison (ADX Florence) and dozens of additional state supermax prisons or supermax‑style units , with historical research finding 57+ facilities across 30–34 states at their peak, though the exact current total changes over time.

Information gathered from public forums or data available on the internet and portrayed here.