How long does breast milk last?

Checked 24 Oct 20262 official publishers, 3 sources

Freshly expressed: 4 days in the fridge, 6 months in the freezer for best quality and 4 hours on the counter.

Official stance

“Never refreeze breast milk after it has thawed.” CDC

“Frozen breast milk that has started to thaw but still contains ice crystals can be refrozen.” CDC

“Start counting the 24 hours when the breast milk is completely thawed, not from the time when you took it out of the freezer.” CDC

Storage times for breast milk by state and place
State	Counter	Fridge 40 °F	Freezer 0 °F
Freshly expressed	4 hours NIH CDC 77°F or colder CDC	4 days CDC NIH	6 months best quality NIH Sources disagree: 6-12 months CDC
Freezer compartment inside the refrigerator	Not stated	Not stated	2 weeks NIH
Refrigerator/freezer with a separate door	Not stated	Not stated	3-4 months NIH
Thawed	2 hours CDC	24 hours CDC NIH	Not recommended CDC NIH
Left over from a feeding	2 hours CDC After 2 hours, leftover breast milk should be discarded. CDC	Not stated	Not stated

Times assume continuous refrigeration at 40 °F or below. When in doubt, throw it out. Freezer times are for quality: “Because freezing 0° F (-18° C) keeps food safe indefinitely, the following recommended storage times are for quality only.” FDA

Sources compared

Source	State	Counter	Fridge	Freezer
CDC 2026	Freshly expressed	4 hours	4 days	6-12 months
MedlinePlus (National Library of Medicine, NIH) 2024	Freshly expressed	4 hours	4 days	6 months
MedlinePlus (National Library of Medicine, NIH) 2024	Freezer compartment inside the refrigerator	-	-	2 weeks
MedlinePlus (National Library of Medicine, NIH) 2024	Refrigerator/freezer with a separate door	-	-	3-4 months
CDC 2026	Thawed	2 hours	24 hours	Not recommended
MedlinePlus (National Library of Medicine, NIH) 2024	Thawed	-	24 hours	Not recommended
CDC 2026	Left over from a feeding	2 hours	-	-

A dash means that source gives no time for that place.

Handling and freezing notes

“Do not store breast milk in the door of the refrigerator or freezer.” CDC
“Store small amounts to avoid wasting milk. Store in 2 to 4 ounces or the amount offered at one feeding.” CDC
“Leave about one inch of space at the top of the container because breast milk expands as it freezes.” CDC
“Never thaw or heat breast milk in a microwave.” CDC
“Breast milk can be stored in an insulated cooler with frozen ice packs for up to 24 hours when traveling.” CDC
“Do not use everyday plastic bags or formula bottle bags. They leak.” NIH

What the sources say

CDC gives freshly expressed breast milk up to 4 hours at room temperature of 77 °F or colder, up to 4 days in the refrigerator, and about 6 months in the freezer as best, with up to 12 months acceptable.¹

CDC notes that freezing keeps food safe almost indefinitely, and that the freezer times are about quality.¹

Thawed milk has much shorter limits: use it within 24 hours if it was thawed in the refrigerator, counting from when it is completely thawed, and within 2 hours once it is brought to room temperature or warmed.¹

CDC says never to refreeze breast milk after it has thawed; its FAQ makes one exception for milk that still contains ice crystals after a power outage.¹³

Milk left in the bottle after a feeding should be used within 2 hours and then discarded.¹

For freezing, CDC suggests small portions of 2 to 4 ounces and about an inch of space at the top of the container, because the milk expands.¹

It also advises storing milk away from the fridge or freezer door, and never thawing or heating it in a microwave.¹

MedlinePlus, the health encyclopedia of the National Library of Medicine, gives the same 4 hours at room temperature and 4 days in the refrigerator for fresh milk.²¹

For a deep freezer kept at a constant 0 °F it lists 6 months, which matches the CDC best-quality time but not the CDC upper limit of 12 months.²¹

MedlinePlus gives shorter limits for other freezers: 2 weeks in a freezer compartment inside the refrigerator, and 3 to 4 months in a refrigerator-freezer with a separate door.²

It also says thawed milk can be refrigerated for up to 24 hours and should not be refrozen, and that everyday plastic bags and formula bottle bags leak.²

Rules that apply here

Freezing and refreezing Thawing safely Fridge and freezer temperature

Milk

Sources

Breast Milk Storage and Preparation | Breastfeeding | CDC. CDC. Dated 2026-08-14. Checked 2026-10-24. At room temperature (77°F or colder) for up to 4 hours.In the refrigerator for up to 4 days.In the freezer for about 6 months is best; up to 12 months is acceptable.Once breast milk is brought to room temperature or warmed, use it within 2 hours.If you thaw breast milk in the refrigerator, use it within 24 hours.Never refreeze breast milk after it has thawed.If your baby did not finish the bottle, use the leftover milk within 2 hours. After 2 hours, leftover breast milk should be discarded.Start counting the 24 hours when the breast milk is completely thawed, not from the time when you took it out of the freezer.Do not store breast milk in the door of the refrigerator or freezer.Store small amounts to avoid wasting milk. Store in 2 to 4 ounces or the amount offered at one feeding.Leave about one inch of space at the top of the container because breast milk expands as it freezes.Never thaw or heat breast milk in a microwave.Breast milk can be stored in an insulated cooler with frozen ice packs for up to 24 hours when traveling.
Breast milk - pumping and storing: MedlinePlus Medical Encyclopedia. MedlinePlus (National Library of Medicine, NIH). Dated 2024-11-08. Checked 2026-10-24. Fresh breast milk can be kept at room temperature for up to 4 hours, and refrigerated for 4 days.In a deep freezer at constant 0 degrees Fahrenheit for 6 monthsIn a freezer compartment inside the refrigerator for 2 weeksIn a separate door refrigerator/freezer for up to 3 to 4 monthsThawed milk can be refrigerated and used for up to 24 hours. Do not refreeze.Do not use everyday plastic bags or formula bottle bags. They leak.
Breast Milk Storage Questions and Answers | Breastfeeding | CDC. CDC. Dated 2023-12-15. Checked 2026-10-24. Frozen breast milk that has started to thaw but still contains ice crystals can be refrozen.
REFRIGERATOR & FREEZER STORAGE CHART. FDA. Dated 2018-03-01. Checked 2026-10-24. Because freezing 0° F (-18° C) keeps food safe indefinitely, the following recommended storage times are for quality only.