Sen. Bernie Sanders, I-Vt., is introducing a bill Wednesday that would expand the Medicare program to all Americans, covering a range of medical services paid for by higher taxes.

But the bill does not spell out how large the tax increase would be, and efforts to pass a single-payer plan at the state level have failed, including in Vermont, where the cost was determined to be too great.

An analysis of a similar plan Sanders introduced when he was running for the Democratic nomination for president, from the left-leaning Urban Institute, projected that such a system would increase federal spending by $32 trillion over a decade. With more costs shifting to the federal government, the analysis projected that the private sector would spend $22 trillion less than it otherwise would have and states would spend $4 trillion less.

The Sanders bill goes into detail about the type of coverage offered, which would pay for emergency surgery, prescription drugs, mental healthcare and eye care without a copay. Plus, people who are 18 and younger would receive a "universal Medicare card" when the law goes into effect, while others who are not currently on Medicare would be phased into the program after four years, according to the Washington Post, which received the bill early.

People who now receive private medical coverage under a job would lose that plan to receive Medicare instead, and their employers would pay higher taxes rather than pay for the cost of private plans. Doctors would be reimbursed by the government; providers would sign a yearly participation agreement with Medicare to remain with the system.

Private health insurance companies would be used to pay for elective treatments, such as plastic surgery, and, according to Vox, the Department of Veterans Affairs plans and the Indian Health Services plans would continue to exist.

The bill, the Medicare for All Act of 2017, will not be able to pass in a Republican-controlled Congress, and is opposed by several Democrats, including House leaders. Still, 15 Democrats are backing the bill, including expected 2020 presidential hopefuls Democratic Sens. Cory Booker of New Jersey, Kamala Harris of California, Elizabeth Warren of Massachusetts and Kirsten Gillibrand of New York.