United States Senator Chuck Grassley (R-IA) (Photo credit: Wikipedia)

By Igor Volsky

Since the Office of Personnel Management (OPM) ruled that the government can continue to subsidize health care coverage for members of Congress who are required to enroll in the Affordable Care Act’s exchanges, a growing number of Republican lawmakers are pledging to forfeit the contribution and are voluntarily withdrawing from their federal insurance plans. The effort represents an attempt by Republicans to put their coverage where there mouths are when it comes to opposing the health care law.

In 2009, Sen. Chuck Grassley (R-IA) offered an amendment to the health care law that required lawmakers and some of their aides to drop their existing health care coverage in the Federal Health Benefits Program (FEHB) and enroll in the insurance exchanges at the core of the health law by 2014. The original Grassley amendment stipulated that Congressional employees “use their employer contribution” to buy insurance through the exchange, but that language never made its way into the final version of the law, leading leaders of both parties and President Obama himself to lobby the OPM to issue a separate rule maintaining the contribution.

The federal government currently covers approximately 75 percent of federal employees’ health care costs and will continue to do so as members and some of their aides enter the exchanges, OPM announced earlier this month. Lawmakers and their staff will not be eligible for the law’s income-based tax credits, which are awarded on a sliding scale to individuals and families between 133 percent and 400 percent of the federal poverty line.

Read More Millionaire Congressman Drops Health Coverage To Protest Obamacare | ThinkProgress.