MAP studies are PSI’s standard tool for monitoring product or service availability. There are two main types of MAP study: coverage and access studies. The sampling methodology used for both study types is usually based on LQAS (Lot Quality Assurance Sampling), which is cost-effective because it uses a relatively small sample size while still allowing for the estimation of nationwide coverage and access rates. MAP studies can provide important information for increasing the efficiency of promotion and distribution activities that are tailored to local needs. This enables social marketers to increase access to health products and services among target populations, maximizing PSI’s health impact.