Breast milk storage: a quick reference

Freshly expressed milk

These CDC home-storage guidelines are for healthy, full-term infants. Follow your care team’s instructions for premature or medically vulnerable babies.

Source: CDC storage times and temperatures.

Thawed milk and unfinished bottles

Use refrigerated thawed milk within 24 hours of complete thawing. Once warmed or brought to room temperature, use it within 2 hours. Do not refreeze thawed milk. Use leftovers within 2 hours after the baby finishes feeding; discard after that. Do not microwave breast milk.

Warming is optional. If you warm milk, use a sealed container in warm water, rather than direct stove heat. Read CDC preparation instructions.

Make labels easy to read

Use milk-storage bags or clean food-grade containers with tight lids. Label the expression date and place milk inside the refrigerator rather than in its door. Use older milk first. An insulated cooler with frozen ice packs can hold milk for up to 24 hours.

Choose a labeling system everyone who handles the milk can understand. Decide where dates will go and what information your childcare provider wants. A consistent label is easier to read at a glance than a mixture of formats and abbreviations.

Leave about an inch of expansion space when freezing. Freeze promptly if you will not use fresh milk within four days. Source: CDC freezing guidance.

Keep a reference with your supplies

Save the original CDC storage page for detailed preparation instructions and printable resources. This summary is a reference, not a way to determine whether a particular bottle is safe after uncertain handling.

If you are uncertain how long milk was stored or what temperature it reached, check current guidance and ask your child’s care team rather than extending a storage time by guesswork. Pair a clear storage plan with your pump-cleaning routine.