- Abeka Testing Service
offers Iowa and Stanford 10 tests
- BJU Press Testing and Evaluation
offers Stanford and Iowa tests
- HSLDA
an extensive page with information about testing as well as sources for tests
- Seton Testing Services
offers CAT, Iowa, and TerraNova tests
- Triangle Education Assessments, LLC
offers group discounts on testing as well as individual tests such as Iowa, Stanford 10, and TerraNova2.
- USA Test Prep
offers test prep courses for many standardized tests for elementary grades up through college admissions and career preparation. You can select courses for particular tests in each state and for individual subjects.