Full List of Police 10-Codes (Printable PDF)

This is the complete ten-code reference: 10-1 through 10-99, with the standard APCO meanings and the notable places where real agencies diverge. It’s built to be printed and kept beside a scanner, so the list comes first, and the explanation comes after. If you want the short version of what actually matters, the variation notes at the end are the part worth reading twice.

Before the list, the one caveat that governs everything below: there is no official national ten-code list. APCO published a recommended set, adoption was voluntary, and departments modified it to suit themselves. What follows is the most widely accepted set of meanings, marked where major agencies disagree.

The Complete Ten-Code List (10-1 to 10-99)

⚠ = known to differ significantly between agencies. See the variation section below.

The Suffixes You’ll Hear Attached

Several codes carry letter suffixes that add the detail that actually matters. These aren’t optional flourishes — the suffix often carries more information than the code.

10-50 (traffic accident) is the most common:

The letter determines the entire response. A 10-50PD gets a report and a wrecker; a 10-50F gets ambulances, a supervisor, and a scene investigation.

Other suffix conventions vary by agency. Some departments append letters to weapons or medical codes to specify the situation — a cardiac case, an unconscious subject, shots fired versus a knife. NYPD, for example, qualifies its ambulance and possible-crime codes this way. If you hear a code with a letter hanging off it, the letter is usually the urgent part.

The Variations That Actually Matter

This is the section to read. Every entry here is a real, live disagreement between real agencies, and each one is capable of producing a serious misunderstanding.

10-1 — “signal weak” vs “officer needs emergency help.” The APCO list says weak signal. Chicago PD uses 10-1 as its officer-in-distress emergency, the most urgent call on the channel. A listener working from a generic list would completely misread the single most important transmission CPD makes.

10-13 — “weather conditions” vs “assist police officer.” In the APCO standard, 10-13 is a request for weather and road conditions. In the NYPD, 10-13 means an officer needs urgent help — the call that drops everything and pulls units from across the surrounding precincts. Two of the most consequential codes in American policing sit on numbers the reference list assigns to mundane business.

10-50 — “traffic accident” vs “officer down.” In Texas and much of the country, a 10-50 is a wreck. In parts of Louisiana, 10-50 means officer down. During hurricanes, manhunts, or pursuits crossing state lines, that gap is a genuine hazard rather than trivia.

10-99 — “wanted/stolen” vs “emergency” vs “one-officer acknowledgment.” Three meanings in circulation. Many agencies use it for a record check returning wanted or stolen. Others use it as an emergency. Chicago uses 10-99 to acknowledge a message from a one-officer car — a neat local touch that tells dispatch the responding unit’s staffing, and nothing like the other two meanings.

10-32 — “person with a gun” vs other local uses. Widely the armed-subject flag, but some jurisdictions assign it to a unit request or a radio check. Given what it means in most places, this is not a code to guess at.

10-23 and 10-54 are milder but still catch people: 10-23 flips between “on scene” and “stand by,” and 10-54 is livestock on the highway in the standard list but a deceased person or another meaning in some agencies.

The pattern is consistent: the codes carrying the highest stakes are among the least standardised. That’s the fundamental problem with the whole system, and it’s why our US 10-codes guide treats the fragmentation as the main story rather than a footnote.

What This List Won’t Cover

Ten-codes are one family among several, and a printed ten-code sheet won’t decode everything you hear.

Response codes are separate: Code 1 (routine), Code 2 (urgent, no lights), Code 3 (emergency, lights and siren), Code 4 (situation under control), Code 7 (meal break). These say how fast, not what.

Signals replace ten-codes across much of the Southeast. Florida runs primarily on Signal 1–100, where Signal 7 is a deceased person and Signal 20 means “under control” on the Highway Patrol but “mentally ill subject” in some counties. A ten-code sheet is close to useless on a Florida channel.

Penal codes are spoken aloud in California — 187 for homicide, 211 for robbery, 459 for burglary — and they’re statute numbers, not radio shorthand.

11-codes are California’s traffic-focused set, where 11-80 through 11-83 grade collisions by severity and 11-99 means officer needs help.

So a California transmission might stack a response Code, an 11-code, and a penal code in one breath, none of which appear on a ten-code list. Our US police code category separates these families out.

Why the Codes Exist — and Why They’re Fading

The ten-code system was built between 1937 and 1940 by Charles Hopper of the Illinois State Police, working with APCO. The “ten” prefix wasn’t decorative. Radios of that era ran on vacuum tubes powered by a dynamotor that needed a tenth to a quarter of a second to spin up to full power, and the first syllable of any transmission was routinely clipped. Saying “ten” first gave the transmitter time to reach power so the number that followed came through intact. The prefix was a throwaway syllable protecting the part that mattered — and it outlived the technology by nearly ninety years.

The system spread, television spread it further, and CB radio in the 1970s pushed 10-4 and “what’s your 20” into everyday English. But the same decentralisation that let it spread also let it fragment, and the fragmentation eventually caught up with it. After inter-agency communication broke down during Hurricane Katrina in 2005, FEMA discouraged ten-codes for multi-agency work, and the Department of Homeland Security’s SAFECOM programme pushed agencies toward plain language. Codes are expressly discouraged in the nationally standardised Incident Command System.

The result is a hybrid. Most departments now use plain language for complex or cross-agency situations and keep codes for routine internal traffic, because “10-4” is still faster and clearer than any alternative. Some agencies have dropped codes almost entirely; small rural departments that rarely work outside their own county have kept the full list. Both are reasonable answers to the same trade-off. Countries that never adopted the system at all, like the United Kingdom, run on plain language and manage fine, as our UK police codes guide shows.

Printing and Using This Sheet

If you’re putting this on the wall, a few practical notes. Keep the ⚠ markers — they’re the difference between a list that informs and a list that misleads. Add your local agency’s name at the top and cross out or correct the entries that don’t match; a sheet annotated for the department you actually listen to beats a pristine generic one every time. Many agencies publish their own code sheets, and where one exists, it overrides everything here.

And don’t try to learn all a hundred. The working vocabulary of a real channel is roughly a dozen codes — 10-4, 10-7, 10-8, 10-20, 10-28, 10-29, 10-38, 10-50, 10-97, 10-98, plus Codes 3 and 4. Those repeat constantly. The other eighty are reference material you’ll consult a handful of times a year, which is exactly what a printed sheet is for. For the wider catalogue across states, agencies, and countries, the master police code lists page collects it all in one place, and our overview of US police codes explains the structure behind it.

Using Police Code to Explore Further

Police Code is a global police code explorer that keeps this reference searchable and, more importantly, keeps it in context. A printed list tells you the standard meaning; a database tells you what the code means at the agency you’re actually listening to, which — as 10-1, 10-13, and 10-50 make plain — is a different question entirely. It’s free to browse and built for scanner listeners, journalists, writers, and anyone who needs a code’s meaning to be right rather than approximately right.