The behavior of absorbed water in equilibrium-swollen poly(acrylamide-co-sodium acrylate) [P(Am-NaA)] hydrogel is studied with H-1 nuclear magnetic resonance (H-1-NMR). The observed non-exponential decay of the spin-spin relaxation data manifests at least two distinguishable environmental states of the absorbed water in all samples. The component, characterized by the relatively shorter T-2, is associated with the more tightly bound water; whereas the other, characterized by longer T-2, might be a combination of near normal and loosely bound water. Attention is directed to the way in which relaxation times and the corresponding fraction of each type of water behave as a function of the crosslink density at 25 degrees C. There is evidence of a sudden change of the crosslink state in P(Am-NaA) hydrogel at crosslink density of about 1.0%.