With his Medicare for All bill introduced in the Senate, backed by sixteen other lawmakers and millions of grassroots advocates, Bernie Sanders pointed the way toward a health care system that works for all Americans. No matter its immediate political future, the the bill provides a foundation on which those who have long fought for universal health coverage can build.

A Census Bureau report released September 12 shows that the Affordable Care Act brought the rate of uninsured people in the United States into the single digits, but coverage in the country lags behind health care systems of other industrialized nations. The percent of Americans whose insurance doesn’t guarantee them access to care has remained persistently high and there are still tens of millions of people who don’t have any medical insurance at all. The new Medicare-for-all bill takes on problems the ACA failed to address in several key ways.

Sanders’s proposal aims at the root causes of runaway health care costs. His proposal would remove control of health care financing from private insurers and place it with the same federal agency that administers Medicare. This would result in huge savings, as the 15 to 20 percent currently siphoned off by private insurers for administrative costs would drop to the range of Medicare’s administration, more like 2 percent. Because private insurers get a cut of all the health care dollars they spend for administrative costs, they have incentive to keep costs high. The Medicare for All proposal puts administration of public health care in public control.

Another source of exorbitant health care costs is prescription drugs. U.S. per capita spending on drugs is much higher than comparable countries—more than double that of the United Kingdom, for example. The Sanders bill responds to this problem by amassing the country’s purchasing power to negotiate drug prices. Our government already obtains fairer drug prices for the Veterans Administration and the Indian Health Service by using their purchasing power. In the Medicare-for-All proposal, the government would use its purchasing power to negotiate fairer drug prices for all Americans.

The senator’s bill also would slash out-of-pocket medical costs. Private insurers allow health care costs to rise and then fold much of those increases into the co-pays and deductibles of people they’re supposed to be insuring. For example, they push high deductible insurance policies which don’t pay the first $1,000, or even the first $3,000 of many patients’ medical bills. The result is a class of people that the Commonwealth Fund refers to as the underinsured: those with out-of-pocket expenses of more than 10 percent of their income, or more than 5 percent if they are below the poverty threshold. Half of these underinsured Americans have problems paying their medical bills and more than 40 percent forego needed care because of out-of-pocket expenses.

The Sanders bill would nearly eliminate cost-sharing for consumers. It states that no deductibles, coinsurance, copays, or similar charges can be imposed for most covered medical services. For drugs and biologics, it would cap annual cost-sharing at $200 per person.

One critical problem left unaddressed in Sanders’s bill is immigrant access to health care. Lack of access to healthcare is a significant source of suffering for the millions of Americans who live and work here without citizenship or immigrant papers. Despite the strong evidence of the economic contributions from these hard-working and law-abiding people, the Sanders proposal punts on the issue of their access to health care, leaving open the possibility that we will continuing to deny it to them.

One critical problem left unaddressed in Sanders’s bill is immigrant access to health care.

Sanders’s bill also contains a concession to health care interest groups that needs to be reconsidered, specifically the way it would improve health care quality. Compared to similar countries, the United States has a long way to go in this area. We have the highest rate of deaths amenable to health care among comparable countries. We have worse records of botched surgeries. A study in the New England Journal of Medicine found that patients received recommended medical care only about half of the time. We need effective policies to improve health care quality, including evidence-based practice guidelines.

Any process for developing practice guidelines to improve health care quality needs to be based on robust evidence, and must stringently minimize conflicts of interest. The last people who should be in the room developing these guidelines are people with substantial financial interests in them. Sanders’s proposal provides that the Cabinet secretary in charge of Medicare “shall consult” with interest groups and could override the findings of research done with independent evidence. Playing politics with health care research this way would endanger lives.

But overall, Senator Sanders is leading the way for the Democratic Party to connect with Americans on one of the issues that matters to them the most, and points the way toward a more humane and just society.