A sixteenth-degree and sixteenth-order spherical harmonic lunar gravity field has been derived from the long-term Keplerian variations in the orbits of the Apollo subsatellites and Lunar Orbiter 5. This model resolves the major mascon gravity anomalies of the lunar nearside and is in very good agreement with line of sight acceleration results. The farside map shows the major ringed basins to be strong localized negative anomalies located in braod regions of positive gravity which correspond closely to the highlands. The rms pressure levels calculated from equivalent surface height variations show that the moon and earth support nearly equal pressures (46 and 57 bars), whereas Mars is appreciably stronger (115 bars). These height variations are equivalent to mean uncompensated loads of 284 kg/cm2 for the moon, 58 kg/cm2 for the earth, and 308 kg/cm2 for Mars. The moon appears to support larger loads than the earth owing to its weaker central gravity field and perhaps a colder upper lithosphere. Significant differences between the low-degree gravity and topography spectra indicate that the longer-wave-length topographic features are isostatically compensated. The effect of compensation reduces the amplitudes of the low-degree gravity harmonics and is responsible for the slower decay in the moon's gravity spectrum. A comparison of the gravity effects of topography for the three planets shows that the moon and Mars support significant topographic features, whereas the earth is nearly in isostatic equilibrium.