A woman explains healthcare benefits at a Covered California event which marks the opening of the state's Affordable Healthcare Act, commonly known as Obamacare, health insurance marketplace in Los Angeles, California, October 1, 2013. REUTERS/Lucy Nicholson

MILWAUKEE (Reuters) - President Barack Obama said on Thursday that some 20 million Americans had become insured as a result of the Affordable Care Act, his signature healthcare law also known as “Obamacare.”

During a trip to Wisconsin to tout the program, Obama said he hoped Republicans would work with him during his final months in office to improve the law, which they have tried unsuccessfully to repeal.

“Today I can announce that thanks to the law, 20 million more Americans now know the security of health insurance,” Obama told a crowd in Milwaukee after being introduced by a local man who said the law saved his life. The man, Brent Brown, said he was a Republican who had not voted for the Democratic president.

The law was passed in 2010 and Republicans have sought to repeal it ever since.

The U.S. Department of Health and Human Services said the estimates Obama referenced included coverage from the expansion of the Medicaid program, health insurance marketplaces, and provisions that allowed young people to stay on their parents’ private insurance plans longer.

The 20 million figure was an update to a September 2015 government estimate that 17.6 million Americans had been insured as a result of the Affordable Care Act.