In this study, an adaptive estimation algorithm is developed to estimate the state of a spacecraft that performs impulsive maneuvers. The accurate tracking of a maneuvering spacecraft with impulsive burns is a challenging problem since the magnitude and the time of occurrence of impulsive maneuvers are usually unknown a priori. To deal with this problem, an adaptive state estimation algorithm is developed in this study using a bank of extended Kalman filters along with interacting multiple models that account for spacecraft motion with and without impulsive maneuvers. Motivated by the fact that impulsive maneuvers usually occur when certain conditions on the spacecraft state are satisfied, the multiple extended Kalman filters are systematically blended using a state-dependent transition probability. Since the information about the conditions based on which impulsive maneuvers occur is explicitly used in the state-dependent transition probability, the proposed algorithm can predict the impulsive maneuvers more accurately and thus produce more accurate state estimates. The proposed algorithm is demonstrated with two illustrative examples: 1) tracking of a geostationary satellite performing station-keeping maneuvers and 2) tracking of a spacecraft performing orbital transfers. Nomenclature B, G = disturbance and control matrix, respectively inc d = maximum allowed inclination error for geostationary satellite k = discrete-time index m i = mode probability for ith mode m ijj = mixing probability from ith mode to jth mode P = state covariance matrix Q, R = covariance matrix of w and v, respectively q = discrete mode index u = control input vector w, v = process and measurement noise, respectively x, y = state and measurement vector, respectivelŷ x = state estimatê x i , P i = ith mode-conditioned state estimate and covariance matrix, respectively y d = maximum allowed along-track error for geostationary satellite ΔT = sampling time πx = state-dependent jump probability π ij x = state-dependent mode transition probability from ith mode to jth mode