How long does breast milk last?
Freshly pumped breast milk lasts up to 4 hours at room temperature, up to 4 days in the refrigerator, and about 6 months in the freezer (up to 12 months is acceptable), according to the CDC. Thawed milk should be used within 24 hours, and warmed milk within 2 hours.
CDC storage times at a glance
| Where the milk is | How long | Counted from |
|---|---|---|
| Room temperature (77°F / 25°C or colder) | Up to 4 hours | pumped |
| Insulated cooler with frozen ice packs | Up to 24 hours | pumped |
| Refrigerator | Up to 4 days | pumped |
| Freezer | About 6 months is best; up to 12 months is acceptable | pumped |
| Thawed in the refrigerator | Use within 24 hours | thawed |
| Brought to room temperature or warmed | Use within 2 hours | warmed |
| Leftover from a feeding | Use within 2 hours, then discard | the feeding began |
- Never refreeze breast milk after it has thawed.
- Never thaw or heat breast milk in a microwave.
Is my milk still good?
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How long can breast milk stay out?
At room temperature, freshly pumped milk can stay out for up to 4 hours. The CDC gives that limit for rooms at 77°F (25°C) or colder.
How long is breast milk good in the fridge?
In the refrigerator, freshly pumped milk keeps for up to 4 days. Store it at the back of the fridge, not in the door: the CDC notes that storing milk further inside helps protect it from temperature changes.
How long does frozen breast milk last?
In the freezer, about 6 months is best, and up to 12 months is acceptable. Leave about an inch of space at the top of the container, because milk expands as it freezes. As with the fridge, keep it away from the door.
If you don’t think you will use freshly pumped milk within 4 days, the CDC says to freeze it right away.
Thawed and warmed milk
- If you thaw milk in the refrigerator, use it within 24 hours.
- Once milk has been brought to room temperature or warmed, use it within 2 hours.
- Never refreeze breast milk after it has thawed.
- Never thaw or heat breast milk in a microwave. Thaw it in the refrigerator overnight, in a bowl of warm or lukewarm water, or under lukewarm running water.
Before feeding, test a few drops on your wrist to check the temperature.
Leftovers from a feeding
If your baby did not finish the bottle, use the leftover milk within 2 hours of the feeding. After that, the CDC says to discard it.
Containers and labels
- Use breast milk storage bags or clean, food-grade containers. Don’t use disposable bottle liners or plastic bags that aren’t made for breast milk.
- Label each container with the date the milk was expressed.
- Store small amounts, 2 to 4 ounces or what your baby takes at one feeding, so less milk is wasted.
Traveling with breast milk
In an insulated cooler with frozen ice packs, breast milk can be kept for up to 24 hours while you travel. When you arrive, use it, refrigerate it or freeze it.
Rules differ by country
Storage advice is not the same everywhere. Brazil's Ministry of Health, for example, recommends much shorter limits: 12 hours in the refrigerator and 15 days in the freezer. Follow the guidance your own health service gives, and ask your pediatrician or lactation consultant about your baby. Read the Brazilian guidance (in Portuguese).
Keep every bag dated in Milkly
Milkly tracks your stash bag by bag, each bag with its own date and location. It keeps the order FIFO so the oldest milk goes first, and shows which bags are near the end of their storage window.
Its storage rules start from these CDC times and can be changed in Settings. Tracking by bag is part of Pro, and your first week is on Pro.
Sources
Last reviewed:
This page summarizes public CDC guidance, which the CDC adapted from the Academy of Breastfeeding Medicine protocol for full-term infants (Protocol #8, 2017). It is not medical advice. If your baby was born early or is in hospital, follow the advice of your baby's care team.