Chase (Sapphire branded only) and Citi cards stipulate 48 months since the last bonus was received for the same card. American Express seems to require 7 years from the time the previous account was closed, but they often send targeted offers without this requirement. It's important to understand not only the amount of time, but the event which starts the clock running. Also, some issuers do not enforce the terms as written. Chase (INK branded only) show a 24 month waiting period that is ignored.