How long can expressed breast milk be stored?

How long can expressed milk be stored?

The CDC page updated on 14 August 2026 lists up to four hours at room temperature of 77 degrees Fahrenheit or colder, up to four days in a refrigerator at 40 degrees or colder, and about six months in a freezer at 0 degrees or colder for best quality. Up to 12 months in a freezer is acceptable, though quality may decrease over time.

The CDC identifies refrigerator and freezer temperatures as 40 degrees Fahrenheit or below and 0 degrees or below. If your appliance doesn’t show its temperature, an appliance thermometer can help you check it. These U.S. recommendations are based on guidance for full term infants. Ask your baby's care team for advice about a premature baby, a baby with health concerns or a feeding plan.

Label and store it carefully

Wash your hands before expressing or handling milk. Use breast milk storage bags or clean food grade glass or plastic containers with tight fitting lids. Label each container with the date it was expressed. Keep it toward the back of the refrigerator or freezer, not in the door, where temperatures change more often.

If you don’t expect to use freshly expressed milk within four days, freeze it promptly. Small amounts can reduce waste. Leave about one inch of space at the top because milk expands when frozen. If milk is going to childcare, label it with the child's name and check the provider's storage requirements.

Thaw and serve milk safely

Thaw the oldest milk first. You can thaw a container in the refrigerator, in warm or lukewarm water, or under lukewarm running water. Don’t thaw or heat breast milk in a microwave, and don’t refreeze it after it has thawed.

For milk thawed in the refrigerator, start the 24 hour limit when it is completely thawed. Once milk is brought to room temperature or warmed, use it within two hours. Breast milk doesn’t need to be warmed and can be served cold or at room temperature. If you warm it, keep the container sealed and use warm water, not direct heat.

If your baby doesn’t finish a bottle, CDC says to use the leftover milk within two hours after the baby finishes feeding. Discard it after that. Follow any different instructions from your baby's doctor or childcare provider.

Keep your log separate from safety guidance

A pumping record can help caregivers remember when milk was expressed. It doesn’t track the milk's temperature or confirm that it was stored safely. Use a dated label and the current storage guidance for those decisions.

A pump log and a storage note describe different things. For a related record keeping question, see how to keep mixed feeding records clear. Ask a doctor about storage questions for a premature or medically vulnerable baby.