Background: Veterans have high rates of psychological symptoms and adjustment problems that trouble them, but many go without professional mental health care due to stigma, logistical challenges, and a high value on self-sufficiency. The number of such Veterans is expected to increase in the next two decades as the proportion of Veterans who served in recent wars increases. To meet Veterans' mental health needs, VHA has invested resources in developing evidence-based, computerized self-help tools. Such online tools can be effective if people use them, but many of the tools do not have strong strategies for engaging Veterans to use them. VHA has also funded a peer support (PS) program aimed at improving engagement in MH care, yet there is little empirical data on how peer support can improve Veterans' psychological health. Combining online tools with peer coaching could leverage the unique strengths of these complementary resources to improve VHA mental health care and improve the overall health of the Veteran population. Use of a VHA-DOD developed online problem-solving training called Moving Forward (MF) has been found to improve problem- solving skills and improve mental health in Veterans preliminary studies, but its use has not yet been studied in VHA primary care patients with clinically significant symptoms. Similarly, preliminary research on PS for an online mental health program has shown an impact on use of the program, but no RCT has been conducted. Research Goals: The overall goal of this research program is to improve mental health care in Veterans by increasing the availability of mental health care that is non-stigmatizing and easily available to Veterans who have untreated mental health problems, but choose not to seek or accept face-to-face VHA mental health care services. The specific aims of this pilot study are preparatory to a large-scale RCT to test the effects of MF with and without peer support on two populations of Veterans who have untreated mental health problems. Aim 1: Test feasibility and acceptability of recruitment and data collection strategies to study MF + PS in two populations of Veterans with unmet mental health needs. Aim 2: Obtain preliminary efficacy results on the impact of MF and MF+PS on problem-solving skills and psychological health in Veterans with unmet mental health needs. Methods: This pilot study aims to investigate the feasibility and acceptability of methods to study the impact of the online problem-solving training, Moving Forward, with and without peer support, in Veterans with untreated mental health problems. We will study 60 VHA primary care patients who are referred for mental health treatment but decline or do not attend a mental health intake session and 60 Veterans living in the community who have untreated mental health problems. We will adapt an existing guide for peer support for an online mental health program for use with MF, train a PS to support use of MF, and monitor fidelity...