This paper examines the price differences between very liquid on-the-run U.S. Treasury securities and less liquid off-the-run securities over the on/off cycle. Comparing pairs of securities in time-series regressions allows us to disregard any fixed cross-sectional differences between securities. Also, since the liquidity of Treasury notes varies predictably over time, we can distinguish between current and future liquidity. We compare a variety of (microstructure-based) direct measures of liquidity to compare their effects on prices. We show that the liquidity premium depends primarily on the amount of remaining future liquidity.