Universal access to basic sanitation and water services and their progressive improvement are important for human development, health, and human rights; and are recognized in program, national, and international policies such as the Sustainable Development Goals (SDGs). Monitoring data are important for measuring progress toward universal access and improvements in service levels. In the SDG era, substantially more data will become available with new and expanded monitoring. Statistically significant inequalities in coverage exist between HCFs by urban-rural setting, managing authority, facility type, and administrative unit. Using frontier analysis, I transformed household monitoring data into indicators of water and sanitation performance. Water and sanitation performance analysis provides policymakers with a new accountability instrument for assessing country progress on meeting full realization of human rights obligations. Improvement opportunities include the use of: relevant and appropriate survey questions, clear definitions, and quality assurance/quality control measures. (Author abstract)