I have several parents who have been told by their doctors that there are no developmental tests for special classroom placement until a child reaches school age. But if we wait until children are in school, catch-up opportunities may be lost.
Actually, standardized tests exist for children of all ages which can elicit information about a number of developmental areas. Many of these tests can be administered by educators, physicians, psychologists, or other professionals who have been trained to do so. What you may be experiencing are physicians who occasionally prefer to wait until a child is older before pursuing formal testing.
When a primary care physician seems less concerned than you about a child's progress in language or motor skills, he/she may have legitimate reasons. Physicians follow the same children for many years and have seen numerous children with mild developmental delays who catch up with their peer group over a period of time without special intervention. When evaluating a child's development in a specific area, this continuity of care over the course of years offers most physicians an advantage.
Educators may also recommend and/or conduct developmental testing. The advantage educators have over physicians is that they observe larger numbers of children (all roughly the same ages) for a period of one to three years. While the duration of observation is limited, the intensity of the observation period and the opportunity for direct comparison to other children is remarkable.
The discrepancy between physicians' and educators' vantage points for child development leads to an occasional disagreement in how to advise parents. An early childhood educator who remains concerned, even after discussing the situation with a child's physician, can and should suggest a developmental assessment. In most states, children under age three can be assessed through publicly-funded programs (Part H of Public Law 99-457). This is often accessible by contacting the public education system in your area. This assessment is available for all children ages three and older in the United States.