It's easy to see how the concept of universal health coverage (UHC) became so elusive.
At the start, the idea must have seemed straightforward enough. Lots of countries "covered" only part of their population, and several were making efforts to expand coverage to "uncovered" populations. China, for example, started out on this process in 2003, trying to expand coverage to the rural population that lost coverage when the old rural cooperative medical scheme collapsed following the de-collectivization of agriculture in 1978.