Yes, usually. Cooked chicken kept at 40°F or below is still within the USDA's 3-to-4-day window on day 3 — just make sure it was refrigerated within 2 hours of cooking.
Three days lands right in the middle of the safe zone for cooked chicken, but that answer only holds if the chicken was handled well from the start.
Cold storage slows bacterial growth, it does not stop it, so the countdown starts the moment the chicken finishes cooking, not when you happen to remember it is in the fridge.
The USDA recommends eating cooked chicken within 3 to 4 days when it is stored at 40°F or below. Day 3 is still inside that window, so chicken refrigerated promptly is generally fine to eat — day 4 is your last safe day before it should be tossed.
A sour or ammonia-like smell, gray or dull color, sliminess on the surface, or visible mold are all reasons to throw chicken out regardless of how many days it has been. Trust your senses over the calendar.
Reheat leftover chicken to an internal temperature of 165°F, checked with a food thermometer at the thickest part. If you are eating it cold, it should still be within that 3-to-4-day window and show no signs of spoilage.
Day 3 is safe territory for chicken that was refrigerated correctly, but treat day 4 as the deadline. When in doubt, a quick smell and temperature check beats guessing.
No — that is past the USDA's 3-to-4-day window for refrigerated cooked chicken, even if it looks and smells fine. Throw it out.
Reheating to 165°F kills most bacteria present at that moment, but it will not remove toxins some bacteria produce after days of growth, so old chicken is not made safe by reheating.
For best quality, use frozen cooked chicken within about 4 months, though it stays safe to eat indefinitely if kept at 0°F.
No — if it sat at room temperature more than 2 hours before refrigeration, throw it away regardless of how it looks.