I asked our doctor about the vest when my daughter turned one. he was all for it, but felt that we needed to wait until age 2. Then my daughter was hospitalized at 14 months. The RT in the hospital brought us the vest for one of her treatments and it went great, after some really badmanual treatments. So the RT started the process, and used the hospitalization as rationale to get it. It worked!!! She's had it for over a year, and minus some difficult days, its been such a blessing.