Charles Dharapak, Associated Press
In this March 28, 2012 file photo, supporters of health care reform rally in front of the Supreme Court in Washington on the final day of arguments regarding the health care law signed by President Barack Obama.

WASHINGTON — Contrary to what you may have heard from its relentless critics, the Affordable Care Act will make more health care of higher quality available to more Americans than ever before.

Claims that it will create a doctor shortage are just the latest attempt to undermine support for the greatest improvement in our nation's health care system in almost half a century.

The United States is indeed facing a shortage of doctors — especially of general practitioners — but health care reform is not the cause.

Rather, as a scholarly study published by the Annals of Family Medicine last year determined, population growth and population aging over the next dozen years will cause 85 percent of the increased need for physicians. Expanded access to medical services offered by the ACA — which we should all agree is a good thing — is responsible for just 15 percent of the shortfall.

In other words, even if we hadn't reformed the health system to give 30 million previously uninsured people access to timely, economical medical care, we would still need a lot more doctors to care for a country that's getting bigger and older all the time.

Why does extending coverage to all those uninsured Americans contribute so little to the doctor shortage?

One reason is that many people were already seeking treatment — although not frequently enough — and usually only in an emergency, when outcomes are worse and costs higher. Also, many of the newly insured will be young and healthy, and so won't be using many medical services again, until a catastrophe hits, at which point we'll all be glad they're insured.

Though Washington didn't cause the impending doctor shortage through health care expansion, it did cause it through irresponsible budgeting.

The federal government pays for most medical residencies, and ever since 1997 — an earlier period of budget "austerity" — the number of resident slots has been capped. Medical schools could turn out more graduates, but hesitate to do so when there are too few residency positions available to accept them.

There's a bipartisan bill in Congress right now to increase residency funding. Unfortunately, it's running into the same shortsighted, indiscriminate budget-cutting mentality that's threatening Head Start for our kids, Meals on Wheels for our seniors, and important scientific research for all of us.

Everyone concerned about the looming doctor shortage should urge Congress to put aside "sequester thinking" and provide adequate funding of medical residency programs.

And instead of finding false problems with the ACA, let's review all the benefits the law has brought and will bring to the American public, including those who are already insured.

Children with pre-existing conditions can now get coverage. Young adults can now stay on their parents' insurance up to age 26. Seniors are now paying less for prescriptions. Insurance companies are now required to spend their ample incomes primarily on patient care, not advertising or lobbying — and if they spend too much on self-promotion, they have to send refunds to their policyholders — the first checks went out last summer.

The Affordable Care Act is a comprehensive approach with a big goal: expanding and improving health care for all Americans.

While detractors do everything in their power to tear it down — most recently by blaming it for the doctor shortage — the ACA will increasingly serve the health-care needs of the American people, guided by the simple but powerful principle that everyone has the right to a healthy life.

Don Kusler is executive director of Americans for Democratic Action.