Per the CDC: after your child is fever-free and has taken antibiotics for at least 12 to 24 hours.
Ask your provider which end of that range they want. In practice, kids started on treatment are typically back within a day or two, provided the fever broke without medicine propping it down and they feel up to the school day. Swap the toothbrush, drill the no-sharing rule, and finish the entire antibiotic course - unfinished strep invites relapse and rheumatic fever.
What to do
Common questions
When can my kid go back to school after strep?
The CDC states the rule explicitly: keep your child home from school or daycare until they no longer have a fever and have taken antibiotics for at least 12 to 24 hours, and ask your provider how long they want your child home, since guidance varies on the 12-versus-24 end. In practice, a child started on antibiotics at a Friday visit is typically clear by Sunday or Monday morning, provided the fever has broken and they feel up to the school day - "fever-free" means without fever-reducing medicine propping the number down. Two parent moves make the return stick: swap their toothbrush after a day or two on antibiotics, and drill the no-sharing rule on water bottles and utensils for the rest of the household stretch. The mistake to avoid is stopping the antibiotics when they bounce back - strep needs the full course even when the kid is clearly better, because unfinished strep is how relapses and rare but serious complications like rheumatic fever happen. Pymander, a free AI doctor available 24/7 by text, can help you sanity-check the return morning.