Home confinement or house arrest—with and without electronic monitoring (or EM)—is an intermediate community corrections program designed to restrict the activities of offenders in the community. This sanction allows offenders to remain in their homes, go to work, run errands, attend school, and maintain other responsibilities. However, their activities are closely monitored (either electronically and/or by frequent staff contacts) to ensure that they are complying with the conditions set by the court. Offenders placed under home confinement are restricted to their residence for varying lengths of time and are required to maintain a strict schedule of daily activities. There are generally two types of home confinement programs: pretrial and postadjudication. Pretrial programs use home confinement as an alternative to detention to ensure that individuals appear in court. Postadjudication programs use home confinement as a sanction that is more severe than regular supervision but less restrictive than incarceration (U.S. Probation and Pretrial Services, 2000). This section is primarily interested postadjudication home confinement programs. Home confinement originated as a program to deal specifically as a sentencing alternative for drunk drivers but quickly expanded to a variety of additional offender populations in numerous jurisdictions (Lilly et al., 1993; Baumer, Maxfield, and Mendelsohn 1993; Baumer and Mendelsohn, 1991; Austin and Hardyman, 1991). This expansion resulted in the number of programs exploding from 95 in 1986 (Renzema, 1992) to more than 1,500 by 1998 (National Law Enforcement and Corrections Technology Center, 1999). However, home confinement programs still generally exclude serious and violent offenders from participation. The diverse types of offenders in home confinement call for programs to operate under various degrees or levels of restriction. These can range from simple curfews to complete lock-downs. For example, the home confinement program of the Federal courts offers three distinct levels of restriction (U.S. Probation and Pretrial Services, 2000). The first level (curfew) requires the program participants to remain at home every day at certain times. The second level (home detention) requires participants to remain at home at all times except for pre-approved and scheduled absences, such as for work, school, treatment, church, attorney appointments, court appearances, and other court-ordered obligations. The most restrictive level, home incarceration, calls for 24-hour-a-day “lock down” at home, except for medical appointments, court appearances, and other activities specifically approved by the court. Many home confinement programs are implemented in conjunction with electronic monitoring (EM). EM encompasses a wide range of systems and components, including home monitoring devices, wrist bracelets, ankle bracelets, field monitoring devices, alcohol and drug testing devices, voice verification systems, and global positioning systems (National Law Enforcement and Corrections Technology Center, 1999). Generally, offenders in an EM program wear a wrist or ankle bracelet that emits a unique signal to a home monitoring device (HMD) in the offender’s home. The HMD communicates with the central computer in a monitoring center through the offender’s telephone line, and is monitored 24 hours a day by a monitoring specialist. Some jurisdictions also require offenders to be employed, attend outside counseling, or participate in educational activities. EM systems can be either “passive” or “active.” A passive system generally requires offenders to answer a telephone and speak to a case officer or insert the transmitter into the HMD to verify their presence at a location. An active system, by contrast, emits a continuous signal from the transmitter to the HMD. If the offender moves out of range, the HMD alerts the central monitoring center. The central monitoring center also may be alerted if a signal indicates a deviation from the preapproved schedule or a violation of a predetermined set of regulations. A violation requires an immediate response from the appropriate agency. Participants who do not comply with the conditions of their supervision face sanctions ranging from a reprimand to violations for new offenses. Close supervision by officers is crucial to the success of home confinement programs (U.S. Probation and Pretrial Services, 2000). Specialists monitor program participants to ensure that they are working, maintaining a stable living arrangement, and not engaging in prohibited behavior such as substance abuse. They also may check monitoring equipment monthly (at least) to make sure that it is functioning properly and there are no signs of tampering. Several studies have examined the impact of home confinement or electronic monitoring on recidivism. Most of the early research suffered from poor research designs, a lack of program integrity, and an exclusive use of low-risk adult offenders (Sherman et al., 1998). These studies indicated that home confinement programs produce a low rearrest rate of about 5 percent (Petersilia, 1987). More recently, several studies examining both pretrial (Baumer and Mendelsohn, 1991) and post adjudication programs (Bonta, Wallace–Capretta, and Rooney, 2000; Austin and Hardyman 1991) found low recidivism rates using experimental designs but no significant difference in recidivism between offenders under electronic monitoring and under close manual supervision. Similar experimental results have been found for juveniles placed under electronic monitoring or traditional home confinement as alternatives to secure detention. In a randomized experiment involving more than 300 juveniles, Wiebush (1992) found that both regular home detention cases and electronically monitored home detention cases had very low rates of recidivism (4 percent and 3 percent, respectively) while in the program. That is, both EM and traditional home detention served equally well as alternatives to detention. This same study examined the efficacy of EM as an enhancement to a post-dipositional ISP, using a separate randomly assigned sample of 288 youth. Half these youth received “regular” intensive supervision, and the other half were placed on EM as part of their intensive supervision. There were no differences between the groups in reoffending rates after six months of follow-up, indicating that EM did not enhance the effectiveness of the ISP program. In summary, home confinement and EM programs appear to consistently result in low recidivism rates for both adults and juveniles when used as a pretrial intervention or postadjudication sentence. The available evidence also indicates that electronic monitoring—while perhaps politically popular—is neither clearly more nor clearly less effective than very close supervision by agency staff. However, both home confinement and EM offer two distinct advantages over incarceration. First, for adults, it reduces the public tax burden by allowing the offender to work. And juveniles are allowed (in fact, required) to continue their schooling uninterrupted. Second, it reduces the human and financial costs associated with incarceration. For example, one estimate places the cost of EM to be between $5 and $25 per day, compared with $50 per day average cost of incarceration (National Law Enforcement and Corrections Technology Center, 1999). Thus, home confinement and EM are viable alternatives in a graduated system not only because they minimize recidivism, but also because they are more cost effective.