If you ladder though, so be aware that T-Bills and T-Notes work slightly differently.

Bills are sold at a discount. The difference between the price you pay and the face value is the interest.

Notes are auctioned as well, but have an interest rate that is paid regularly. The yield is a combo of the discount and the interest paid. If the yield is lower than the interest rate, you will pay more than face value for the note, but will get regularly interest payments.