Say where the milk is and when it was pumped — or thawed, or warmed, or when the feed ended — and get the time it is good until, by the CDC’s limits. The Academy of Breastfeeding Medicine’s protocol, which the CDC’s page is built on, allows longer in a couple of places; you see its figure too, but the answer uses the stricter one.
Freshly pumped, on the counter
Up to 4 hoursthe CDC: at room temperature (77°F or colder)
What each source says
These times are for a healthy, full-term baby at home — the scope of the breastfeeding doctors’ protocol. For a premature or hospitalised baby, follow the hospital’s rules, which are stricter. When in doubt, throw it out.
Storage times checked 2026-09-25.
Quick answer: the CDC says freshly pumped breast milk keeps up to 4 hours at room temperature (77°F or colder), up to 4 days in the fridge, and in the freezer about 6 months is best; up to 12 months is acceptable. Milk thawed in the fridge: use it within 24 hours of being completely thawed. Once it is warmed or at room temperature: within 2 hours. A bottle your baby did not finish: within 2 hours, then throw it out. Never refreeze thawed milk.
How to use it
Pick where the milk is — the counter, the fridge, the freezer, a cooler with ice packs, thawed in the fridge, warmed, or left over from a feed — and the date and time on the bag, or when it was thawed, warmed or finished with. The timer gives the time it is good until and how long is left, with each source’s own words beside it. It keeps counting while the page is open. The link keeps the bottle and the time, so Copy link sends it to whoever is doing the next feed.
Where the CDC and the breastfeeding doctors differ
The CDC’s page is adapted from the Academy of Breastfeeding Medicine’s Clinical Protocol #8 (revised 2017), and on most rows they agree. On three they do not. On the counter, the ABM calls 4 hours optimal and 6–8 hours acceptable under very clean conditions; the CDC says up to 4. In the fridge, the ABM allows 5–8 days under very clean conditions; the CDC says up to 4. For a bottle your baby has drunk from, the ABM says it “seems reasonable to discard the remaining milk within 1–2 hours”; the CDC says 2. The timer’s answer uses the stricter limit every time and shows the other, marked as the other — between the two it says caution, not fine.
Thawing, and the two things never to do
Thaw the oldest milk first: in the fridge overnight, in warm or lukewarm water, or under lukewarm running water. The CDC: “Never thaw or heat breast milk in a microwave. Microwaving can destroy nutrients in breast milk and create hot spots, which can burn a baby’s mouth.” And “Never refreeze breast milk after it has thawed” — the ABM says that no recommendation can yet be made on refreezing, so the CDC’s never is the rule here.
Why the freezer times are about quality
The CDC is explicit: “Although freezing keeps food safe almost indefinitely, recommended storage times are important to follow for best quality.” So in the freezer the timer says best until at 6 months and acceptable until at 12, and past 12 months it says the milk is past the recommended time — not that it is dangerous.
Who these times are for
A healthy baby born at term, at home: that is the scope of the ABM’s protocol. A baby who was born early or is in hospital is fed by the hospital’s milk rules, which are stricter — follow those. And whatever a timer says, milk that has been somewhere warm is not worth the risk: when in doubt, throw it out.
Pumping and storage guides on Best & Right
Bags that do not leak in the freezer: breast milk storage bags. Travelling with it: flying with formula and breast milk. And the pump itself: the best-rated breast pumps.