Breast Milk Storage Guidelines Chart

CDC breast milk storage chart

CDC guidelines for healthy, full-term infants. Always use the oldest milk first.

Type of milk	Room temp (77F / 25C)	Fridge (40F / 4C)	Freezer (0F / -18C)
Freshly expressed or pumped	Up to 4 hours	Up to 4 days	6 months best, up to 12 months
Thawed, previously frozen	Up to 2 hours (once warmed)	Up to 24 hours	Never refreeze
Leftover from a feeding	Use within 2 hours of finishing	Use within 2 hours of finishing	Do not store

How to read the chart

The top row covers milk you have just pumped: 4 hours on the counter, 4 days in the fridge, and up to 12 months frozen, though using frozen milk within 6 months keeps its quality highest. Cooler is always safer, so refrigerate or freeze milk as soon as you can.

Once milk has been frozen and thawed, the windows shrink. Thawed milk lasts up to 24 hours in the fridge and only about 2 hours once brought to room temperature or warmed, and it can never be refrozen. Milk left over after a feeding should be used within 2 hours of your baby finishing, then discarded.

Thawing and warming the right way

Frozen milk needs gentle handling to stay safe and to keep its nutrients.

• Thaw the oldest milk first, in the fridge overnight, in a bowl of warm water, or under lukewarm running water
• Never thaw or heat breast milk in a microwave: it heats unevenly, creates hot spots, and can damage the milk
• After thawing in the fridge, use the milk within 24 hours, counting from when it is fully thawed
• Once thawed and warmed to room temperature, use within 2 hours and never refreeze it
• Swirl thawed milk gently to remix the fat layer; do not shake hard

Storing milk so it lasts

• Store milk in clean, food-grade containers or milk-storage bags, leaving room at the top since milk expands when frozen
• Keep milk toward the back of the fridge or freezer, not in the door, where the temperature is most stable
• Label every container with the date you pumped, and use the oldest first
• Freeze in small 2-to-4 oz portions to limit waste and thaw only what you expect to use
• It is fine to add freshly pumped milk to already-chilled or frozen milk, but cool the fresh milk in the fridge first

Reflects the CDC human-milk storage guidelines current for 2024-2026 (4 hours room temp, 4 days fridge, 6-12 months freezer).

Related questions

Can I refreeze breast milk that has thawed?

No. Once breast milk has thawed, never refreeze it. Use thawed milk within 24 hours if it stays in the fridge, or within about 2 hours once it has been warmed to room temperature, then discard whatever is left.

Can I combine milk from different pumping sessions?

Yes, but cool the fresh milk in the fridge before adding it to milk that is already cold or frozen, so you do not partially thaw the stored batch. Label the combined container with the date of the oldest milk and use it within that batch's window.

Does the storage clock change for a premature or sick baby?

It can. The standard chart is for healthy, full-term infants; hospitals often use stricter limits for premature or medically fragile babies. If your baby was born early or has health concerns, follow the guidance your care team gives you.

Why does my thawed milk smell soapy?

A soapy or metallic smell after thawing is usually from an enzyme called lipase breaking down fats, and the milk is still safe to use. If your baby refuses it, you can scald fresh milk briefly before freezing future batches to reduce the change.

Sources & further reading

1. CDC — Breast Milk Storage and Preparation
2. CDC — Breast Milk Storage Questions and Answers
3. AAP HealthyChildren — Storing and Preparing Expressed Breast Milk

This article reflects current AAP, CDC, FDA, and other public-health guidance and is for educational purposes only. It does not constitute medical advice. ParentFlow is a wellness companion — not a substitute for your pediatrician. For any medical concern, contact your healthcare provider.