The use of acute, short-term residential care for opioid use disorder has grown rapidly, with policy makers advocating to increase the availability of "treatment beds." However, there are concerns about high costs and misleading recruitment practices. We conducted an audit survey of 613 residential programs nationally, posing as uninsured cash-paying individuals using heroin and seeking addiction treatment. One-third of callers were offered admission before clinical evaluation, usually within one day. Most programs required up-front payments, with for-profit programs charging more than twice as much ($17,434) as nonprofits ($5,712). Recruitment techniques (for example, offering paid transportation) were used frequently by for-profit, but not nonprofit, programs. Practices including admission offers during the call, high up-front payments, and recruitment techniques were common even among programs with third-party accreditation and state licenses. These findings raise concerns that residential programs, including accredited and licensed ones, may be admitting a clinically and financially vulnerable population for costly treatment without assessing appropriateness for other care settings.