Rate proposals for insurers that plan to participate in the Obamacare exchanges next year range from a 5 percent reduction in cost in Providence, R.I., to an increase of 49 percent in Wilmington, Del., an analysis from the Kaiser Family Foundation shows.

Those increases in insurance premiums for the most part will be subsidized by the federal government, but individuals who make more than $48,000 a year are vulnerable to premium hikes that may take a significant toll on their finances or make them leery of buying coverage.