The "where you buy" question matters more than the card
Diapers, formula, and wipes are the highest-frequency baby purchases, and they're available at every major retailer — drugstores (Walgreens, CVS), supermarkets (Kroger, Publix), warehouse clubs (Costco, Sam's), and discount stores (Walmart, Target). The card that wins depends on where you buy, not just what you buy:
- Drugstores → rotating 5% cards (Freedom Flex's Q1/Q3 categories) or US Bank Cash+
- Supermarkets → Amex Blue Cash Preferred (6%) up to the cap, Amex Gold (4× MR) above it
- Costco / Sam's → Costco Anywhere Visa (2%) or Sam's Mastercard (5% online)
- Walmart / Target → no major card gives bonus earn here; use your best flat-rate card (2%)
If you can shift most diaper-and-formula buying from drugstores to grocery stores or warehouse clubs, you typically earn an extra 3–4 percentage points on the same dollars — usually worth more than picking the "right" drugstore card.