This study compared experts' views on the critical ingredients of assertive community treatment and intensive case management. Twenty experts on assertive community treatment and 22 experts on intensive case management rated the importance of 40 elements common to each treatment approach. The assertive community treatment experts gave higher importance ratings than the intensive case management experts to 37 of the 40 items; for 21 of these items, the ratings were significantly higher. Differences in importance ratings were greatest for organizational and structural elements and smallest for treatment goals. The results of this study indicate that although intensive case management resembles assertive community treatment in most respects, assertive community treatment may be a more clearly articulated model overall.