The HCTC was enacted as part of the Trade Act of 2002. As originally enacted, it provided a 65-percent tax credit for qualifying health coverage (including COBRA continuation coverage).
The Trade Adjustment Assistance Extension Act of 2011 (H.R. 2832) increases the HCTC from 65 percent to 72.5 percent and extends the HCTC program though Jan. 1, 2014.
The HCTC program is explained in detail in Mandated Health Benefits: The COBRA Guide.