CDC Breast Milk Storage Guidelines
Breast Milk Storage Guidelines: How Long Breast Milk Lasts
Freshly pumped breast milk lasts up to 4 hours at room temperature, up to 4 days in the fridge, and about 6 months in the freezer. Up to 12 months in the freezer is acceptable.
Thawed milk lasts 24 hours in the fridge. Never refreeze thawed milk. Use warmed milk and bottle leftovers within 2 hours.
These are the CDC breast milk storage guidelines, last updated August 2026.
Breast Milk Storage Chart
How Long Breast Milk Lasts: Storage Chart
These times are for freshly expressed breast milk in a clean container with a tight lid.
Room Temperature
Up to 4 hours, at 77°F (25°C) or colder.
Refrigerator
Up to 4 days. If you won't use it in 4 days, freeze it right away.
Freezer
About 6 months is best. Up to 12 months is acceptable.
Insulated Cooler
Up to 24 hours with frozen ice packs. Then use, refrigerate or freeze it.
Thawed Milk
Up to 24 hours in the fridge, counted from when it is fully thawed. Never refreeze.
Warmed Milk and Leftovers
Use within 2 hours. Throw away what is left in the bottle after that.
Source: CDC: Breast Milk Storage and Preparation, last updated August 2026. If your baby is premature or in the hospital, follow your care team's storage rules. They may be stricter. See Breast Milk Storage for NICU: Pumping and Transport Tips.
Room Temperature
How Long Can Breast Milk Sit Out?
Freshly pumped breast milk can sit out for up to 4 hours at room temperature. That is 77°F (25°C) or colder.
Milk that was thawed or warmed is different. Use it within 2 hours.
Freshly Pumped Milk
Up to 4 hours at room temperature. After that, refrigerate or freeze it.
Thawed or Warmed Milk
Use within 2 hours once it reaches room temperature or is warmed.
Leftover Milk in a Bottle
Use within 2 hours after your baby finishes feeding. Then throw it away.
Refrigerator
How Long Is Breast Milk Good in the Fridge?
Freshly pumped breast milk is good for up to 4 days in the fridge.
If you won't use it within 4 days, freeze it right away. Freezing it early keeps more of its quality.
Fresh Milk: Up to 4 Days
Store it at the back of the fridge, not in the door, where the temperature changes more.
Thawed Milk: Up to 24 Hours
Count 24 hours from when the milk is fully thawed, not from when you took it out of the freezer.
Label Every Container
Write the date the milk was expressed, so you use the oldest milk first.
Freezer
How Long Is Frozen Breast Milk Good For?
Frozen breast milk is best used within about 6 months. Up to 12 months is acceptable.
Freezing keeps milk safe for a long time, but quality drops the longer it is stored. That is why the oldest milk should be used first.
Freeze Small Amounts
Freeze 2 to 4 ounces per bag, or the amount your baby drinks at one feeding. Less milk goes to waste.
Leave Room to Expand
Leave about an inch of space at the top. Breast milk expands as it freezes.
First In, First Out
Keep the oldest bags in front and use them first. Store bags flat, so they take up less freezer space.
Thawing and Warming
How to Thaw and Warm Breast Milk
Thaw the oldest milk first. Thaw it in the fridge overnight, in a bowl of warm or lukewarm water, or under lukewarm running water.
Never thaw or heat breast milk in the microwave or on the stove.
Warming Is Optional
Your baby can drink breast milk cold, at room temperature or warmed. If you warm it, keep the container sealed and test a few drops on your wrist.
Swirl, Don't Shake
The fat in breast milk can separate. Swirl the milk gently to mix it back in.
Never Refreeze Thawed Milk
Once breast milk is thawed, use it within 24 hours in the fridge or 2 hours at room temperature.
How to Store Breast Milk
How to Store Breast Milk Safely
Use breast milk storage bags or clean glass or plastic containers with tight lids. Don't use disposable bottle liners or plastic bags that aren't made for breast milk.
Wash your hands with soap and water before you pump or handle milk.
Label With the Date
Write the date the milk was expressed on every container. For daycare, add your baby's name too. Cubtale labels are pre-numbered, so there is no handwriting.
Use Bags Made for Breast Milk
Freezer-safe bags take less space and freeze flat. Cubtale breast milk storage bags are pre-sterilized, BPA-free and double sealed.
Keep Pump Parts Clean
Clean your pump parts after every session. See How to Clean and Sanitize Pump Parts.
Breast Milk Stash Tracker
Track Your Breast Milk Stash and Expiration Dates
Cubtale is a pumping tracker app that follows the CDC breast milk storage guidelines for you. Save each bag with its amount, pump date and location. Cubtale sets the expiration date and alerts you before milk expires.
Numbered Cubtale labels link each bag to the app. You see how much milk you have in the fridge and freezer, and which bag to use next.
Expiration Alerts
Each bag's expiration is set from where it is stored: room temperature, fridge, freezer or deep freezer.
First In, First Out
The oldest bag is always next, so nothing gets forgotten at the back of the freezer.
Caregivers Stay in Sync
Partners, grandparents and daycare can scan the label and mark milk as used. You get notified.
Breast Milk Storage FAQ
How long is breast milk good for?
Freshly pumped breast milk is good for up to 4 hours at room temperature, up to 4 days in the fridge, and about 6 months in the freezer. Up to 12 months in the freezer is acceptable. These are the CDC guidelines.
How long can breast milk sit out?
Up to 4 hours at room temperature, 77°F (25°C) or colder. Thawed or warmed milk should be used within 2 hours.
How long is breast milk good in the fridge?
Up to 4 days for freshly pumped milk. Thawed milk is good for 24 hours in the fridge, counted from when it is fully thawed.
How long is thawed breast milk good for?
Up to 24 hours in the fridge after it is fully thawed. Once it is at room temperature or warmed, use it within 2 hours.
Can you refreeze thawed breast milk?
No. The CDC says never refreeze breast milk after it has thawed.
Can you put breast milk back in the fridge after warming it?
The CDC says to use warmed breast milk within 2 hours. Milk left in the bottle after a feeding should be thrown away after 2 hours.
Do you have to warm breast milk?
No. Your baby can drink breast milk cold, at room temperature or warmed. If you warm it, use warm water, never the microwave.
How much breast milk should I freeze in each bag?
Freeze 2 to 4 ounces, or the amount your baby drinks at one feeding. Leave about an inch at the top for the milk to expand.
How long does breast milk last in a cooler?
Up to 24 hours in an insulated cooler with frozen ice packs. When you arrive, use the milk, put it in the fridge, or freeze it.
Can I store breast milk in the fridge door?
No. Store breast milk at the back of the fridge or freezer, not in the door, where the temperature changes more.
Are storage guidelines different for premature babies?
They can be. If your baby is premature or in the NICU, follow your hospital's rules. They may be stricter. See Breast Milk Storage for NICU: Pumping and Transport Tips.
How can I keep track of breast milk expiration dates?
Label every container with the date. Cubtale does this for you: save each bag with its amount, date and location, and Cubtale sets the expiration from the CDC guidelines and alerts you before milk expires. See how the Cubtale pumping tracker works.
