A new analysis from the Kaiser Family Foundation reveals wide variation across local communities in the share of the population that could benefit from coverage expansion in the Affordable Care Act (ACA) starting in 2014.

In parts of Florida, New Mexico, Texas, Louisiana, and California, as much as 40% of the non-elderly population could benefit from the expansion of Medicaid or through tax credits to help purchase coverage in the new health insurance exchanges. By contrast, many parts of states such as Massachusetts, Hawaii, New York and Connecticut – which already have high levels of employer-sponsored insurance or reforms that make coverage more accessible and affordable – will see as little as 2% of the population benefitting from the ACA’s coverage expansion.

The new analysis estimates the share of the non-elderly population in over 2,000 geographic areas across the U.S. who had family income up to four times the poverty level in 2010 and were either uninsured or buying coverage on their own. Starting in 2014, people with family incomes up to 138% of the poverty level ($31,809 for a family of four and $15,415 for a single person in 2012) will be generally eligible for the Medicaid program. People buying coverage in the new state-based health insurance exchanges will be eligible for federal subsidies to subsidize the cost of insurance if their income is below four times the poverty level ($92,200 for a family of four and $44,680 for a single person in 2012).

The analysis includes an interactive tool that allows users to enter in their zip codes and see the percentage of people in their communities who could be helped by subsidies to help pay for private insurance or eligible for Medicaid starting in 2014 under the ACA.