There is not a yearly or monthly limit for earning 1% cashback*! For purchases that earn more than 1% cashback:
Yearly: For purchases with a rewards rate higher than 1%, you can earn up to $25,000 in cashback at the higher rewards rate. After you reach $25,000, you will receive 1% cashback on the remainder of purchases that qualify for the higher rewards rate for the remainder of the calendar year.
Monthly: Purchases with a rewards rate higher than 1% are limited to $150 in cashback per merchant within a calendar month, after which you will receive rewards at a rate of 1% at that merchant for the remainder of the calendar month.