The standard peacetime status of all Starfleet vessels. Crew members perform their regular routine duties; while off-duty they may engage in personal hobbies, continue research on their own time, fraternize, utilize the holodeck, enjoy the ship's library, or sleep. The mandatory bridge crew on a capital ship on condition green consists of a command officer, a flight control officer (or helmsman), a sensor operator (usually a science officer or operations manager), and (if the Federation is in a state of emergency) a weapons or tactical officer (who can also serve as navigator or operations manager on some ships). Some captains maintain a full bridge crew even on condition green. Even on condition green, navigational deflectors are up, forty percent of ship's weapons are on standby status able to power up in two minutes, and one shuttle remains ready for launch in five minutes. While on condition green, the operations manager or first officer runs a level 4 diagnostic check of primary ship systems every eight hours.

The senior bridge officer (or the captain or first officer at any time) can place the ship on yellow alert. A yellow alert signals the possibility of combat, hazardous flight conditions, or ship system malfunction. On yellow alert, sleeping personnel wake, dress and equip themselves. Off-duty personnel stand in quarters for assignment to their departments. Senior bridge crew report for duty. On some ships, or during wartime, unarmed on-duty security personnel arm themselves. All crew members keep a special eye out for anything out of the ordinary, reporting any strange readings, damage, or occurrences. Ship's weapons arm, and the operations manager clears the decks of low-priority systems use such as holodecks, scientific experiments or surveys, and so forth. The operations manager or first officer runs a level 4 diagnostic check of the entire ship immediately.

Only the captain or the senior bridge officer can order red alert. In theory, ships should go to yellow alert first, which should bring the captain to the bridge to decide on red alert status. In practice, crises don't always wait for turbolifts. On red alert, all personnel head to duty stations. Security personnel fan out to transporter rooms and other strategic locations throughout the ship. Medical personnel report to sickbay and other duty stations. Engineers check and wait near critical systems. All shuttle crews report to shuttlebays, and all shuttles warm up. Weapons arm and load; shields come up. Active sensors begin sweeps at all ranges. The computer automatically runs a level 4 diagnostic check continuously.

This operational mode is similar to yellow alert but focuses on an internal breach of security. During an intruder alert, all nonessential personnel are confined to their quarters or duty stations for the duration of the emergency. Movement through the ship requires the authorization of an immediate superior officer and all turbolifts key to authorization codes only. Armed security teams patrol each deck, with teams stationed at sensitive areas of the ship (e.g., transporter rooms, shuttlebays, torpedo bays, main engineering, computer core, armory, and the bridge). The security officer mounts a full internal scan of the ship, ready to seal bulkheads, flood the decks with anaesthezine, or any other response required.

In the event of an outbreak, this operational mode confines all personnel to their current locations, while environmental controls isolate life support systems for each deck. This ensures the contagion does not spread throughout the starship or facility. Priority power is routed to sickbay, and the chief medical officer runs a full internal scan of the ship to locate and deal with any contagion.

If the commanding officer considers the vessel lost, he/she may give the order to abandon ship. All shuttle crews ready their craft and prepare for immediate departure. If a habitable planet is in range, ship's power transfers to all working transporters. All personnel report to a designated mustering station in the event of an abandon ship order being issued, with the key supplies on their evacuation roster. Lifeboats are enabled, and launched either by the bridge or by their occupants. A microwarp buoy is launched, containing a subspace transmitter and a copy of the ship's logs. The operations manager or first officer oversees the evacuation of the ship while the rest of the bridge crew works to contain the emergency that caused this drastic measure.