SUMMARY: This is Part 4 of our series on key issues of the presidential election. We'll distill the candidates' positions and examine key rulings. This time, health care.

In an ongoing series, we're examining issues from the presidential campaign. For each topic, we’ll distill the candidates' positions and present some key rulings. Part 1 was taxes. Part 2 was Iraq. And Part 3 was energy. This week, we take on health care. Read all our rulings on health care here.

THEIR PAST POSITIONS AND THEIR PLANS

John McCain

• Ends the longtime tax exemption on employer-provided health insurance and replaces it with a $2,500 credit. This move aims to create more competition among health insurance providers and improve efficiency.

• Will ask the states to help create coverage plans to insure those with pre-existing conditions. Promotes electronic recordkeeping and greater access to preventive care.

Barack Obama

• Workers who like their health care plan keep their coverage. Other can buy affordable coverage through national pools.

• Increases eligibility for the poor and children to enroll in initiatives like Medicaid and the State Children’s Health Insurance Program. Also promotes electronic recordkeeping and preventive care.

Analysis: Independent groups like the Commonwealth Fund found that McCain would cover an additional 2-million of the uninsured, while Obama would cover additional 34-million. By 2018, McCain’s plan would cost $1.3-trillion; Obama’s plan would cost $1.6-trillion. “Obama’s proposal for mixed private-public group insurance ... has greater potential to move the health care system toward high performance than does McCain’s proposal to encourage individual market coverage through the use of tax incentives and deregulation,” its report concludes. You can read the report here.

Key rulings for McCain

• On his plan: During a debate, McCain said he wants to give "every American a $5,000 refundable tax credit." However, his plan is to give only $2,500 to individual Americans, and $5,000 to couples. We ruled this claim Half True.

• On Obama's plan: In the same debate, McCain said that Obama's plan calls for "mandates and fines for small businesses." But Obama's plan does not mandate coverage, except for children. And while employers who don't offer coverage to their employees are required to contribute to a national pool, that's hardly a fine. Not to mention that small businesses are exempt from contributing to the pool. We ruled this False.

Key rulings for Obama

• On his plan: Again in a debate, Obama said that under his proposal, "if you've got a health care plan that you like, you can keep it." He's right. He advocates a program that seeks to build on the current system, rather than dismantling it and starting over. We ruled this True.

• On McCain's plan: In a TV ad, Obama said that McCain's plan "leaves you on your own to pay McCain's health insurance tax." McCain proposes repealing the long-standing tax exemption on employer-provided insurance. But in exchange, he proposes a tax credit of $2,500 per person to spend on any health insurance they wish. So McCain’s health plan does not leave you “on your own” to pay health insurance tax. His plan gives you a credit to work with. We rate Obama’s statement Barely True.