Most babies are ready to stop formula at 12 months old. At that point, you can switch to plain, unsweetened whole cow’s milk or a fortified dairy alternative. This is the standard recommendation from both the CDC and the American Academy of Pediatrics, and it applies to full-term, healthy infants who are eating a variety of solid foods.
Why 12 Months Is the Cutoff
Formula exists to deliver a precise balance of proteins, fats, vitamins, and minerals that a baby’s body needs during the first year but can’t get from regular food or milk alone. Cow’s milk, while nutritious for older children, creates real problems for younger babies.
Before 12 months, cow’s milk has too much protein for a baby’s developing kidneys to process efficiently. It also lacks adequate iron and can cause tiny micro-bleeds in an infant’s digestive tract, which further depletes iron stores. Combined, these factors put babies at risk for iron-deficiency anemia, one of the most common nutritional deficiencies in early childhood. Formula is specifically designed to avoid all of these issues, which is why it remains the recommended milk source (alongside breast milk) for the entire first year.
Premature Babies Follow a Different Timeline
If your baby was born early, the 12-month mark is based on adjusted age, not the calendar birthday. Adjusted age accounts for how early your baby arrived. So a baby born two months premature would typically continue on formula until roughly 14 months after birth. The AAP recommends that formula-fed preterm infants stay on specialized preterm formulas until they reach the 5th to 10th percentile on standard growth curves or hit 1 year adjusted age.
How to Make the Switch
You don’t have to swap formula for milk overnight. A gradual transition over one to two weeks tends to work best, both for your baby’s digestion and their willingness to accept the new taste.
One approach: start by replacing a single formula feeding with about an ounce of whole milk in a sippy cup. Children’s Hospital of Philadelphia notes that it’s fine to introduce a small amount of whole milk as early as 11 months for a couple of weeks before making the full switch at 12 months. If your baby doesn’t like the taste, try mixing equal parts whole milk and prepared formula, then gradually shift the ratio toward all milk over the course of a week or two.
Once your child is fully transitioned, stick to whole milk rather than reduced-fat versions. Toddlers need the fat content in whole milk for brain development. Most pediatricians recommend keeping total milk intake to about 16 to 24 ounces per day. Going beyond that can fill your toddler up, crowd out iron-rich solid foods, and ironically lead to the same iron-deficiency problems that make cow’s milk risky before 12 months.
You Don’t Need Toddler Formula
Walk down any formula aisle and you’ll see “stage 3” or “toddler” formulas marketed for children 12 months and older. These products are generally unnecessary. The AAP has stated directly that toddler formulas are “nutritionally incomplete” and “offer no benefit over much less expensive cow’s milk in most children older than age 12 months.” They’re also not a substitute for standard infant formula in babies under 12 months.
For a healthy toddler eating a varied diet with fruits, vegetables, grains, and protein sources, whole cow’s milk provides everything these pricier products claim to offer. The marketing around toddler formula can make parents feel like they’re missing something, but for the vast majority of kids, regular milk and a balanced diet are all that’s needed.
Plant-Based Milk Alternatives
If your child has a cow’s milk allergy or your family avoids dairy, fortified plant-based milks (soy, oat, almond, coconut, cashew, or rice) can work as a substitute after 12 months. The key word is “fortified.” The vitamin and mineral content varies significantly between brands and types, so check the label for added calcium and vitamin D at minimum. Choose unsweetened, unflavored versions.
Not all plant milks are nutritionally equivalent to cow’s milk. Soy milk tends to be closest in protein content, while almond and rice milks are often much lower. If you’re using a plant-based alternative as your child’s primary milk, it’s worth discussing the specific brand with your pediatrician to make sure it fills the nutritional gaps left by skipping dairy.
Signs Your Baby Is Ready
Age is the primary factor, but readiness also depends on how well your baby is eating solid foods. By 12 months, most children are eating three meals a day with snacks and getting a wide range of nutrients from food rather than relying on formula as their main calorie source. If your baby is still struggling with solids at 12 months or has specific medical conditions affecting growth or nutrient absorption, the timeline for stopping formula may shift. In those cases, your pediatrician can help determine when the switch makes sense.