Annual Medicare spending is expected to double over the next 10 years, as baby boomers age and people live longer on average. And Medicaid will also see greater demand given that it provides coverage to more than 4.6 million low-income seniors. Experts are already concerned about funding these programs — and the tax law passed in late 2017, which is expected to add about $1.5 trillion to the federal deficit, poses new challenges. Federal responses to a ballooning deficit could put the health and financial security of future seniors at stake.