Sometimes married life is blissful – intimacy and companionship are easy, feelings of trust and commitment are strong, partners treat one another with love and consideration, and the marriage seems indestructible. Unfortunately, many couples encounter periods when life is not so easy – times when intimacy and companionship are hard work at best, good times are a distant memory, trust and commitment are sorely strained, and the marriage verges on collapse. Much of married life unfolds in a middle ground between these extremes, in a state where good times are punctuated by dissatisfying incidents of greater or lesser intensity. The manner in which couples negotiate this intermediate state appears to be crucial to maintaining a long-term, enduring marriage. This chapter deals with one important feature of the “middle ground” of marriage by analyzing an interaction phenomenon termed accommodation. Interaction sequences involving accommodative behavior are initiated when one partner engages in a potentially destructive act, such as behaving in a thoughtless manner, saying hurtful things, yelling at the partner, or worse. Accommodation refers to an individual's willingness, when the partner has enacted a potentially destructive behavior, to (a) inhibit impulses to react destructively in turn and (b) instead behave in a constructive manner.