Former vice president Joe Biden and Sen. Kamala D. Harris (D-Calif.) muddled through key details of their health policies Wednesday night at the Democratic presidential debate, health-care experts said, leading to a confusing series of disagreements over their proposals.

The dispute pitted two of the leading primary contenders against each other from the beginning of the debate, with Biden and Harris accusing the other of mischaracterizing their health-care policies.

Health-care experts said both candidates strained to explain key details.

Biden misled viewers when he said during a heated exchange that his proposal would cover everyone — even though by his own plan’s admission, it would leave out 3 percent of Americans, or about 10 million people.

Harris downplayed the impact of her proposal on employer-sponsored plans in an exchange with Sen. Michael F. Bennet (D-Colo.), according to health experts.

Both Harris and Biden have stopped short of the Medicare-for-all plan endorsed by Sen. Bernie Sanders (I-Vt.) and Sen. Elizabeth Warren (D-Mass.), which would put all Americans into one single government insurer with no premiums, deductibles, or co-pays. That plan, sometimes called a single-payer plan, is more far-reaching, and would require larger middle-class tax increases.

But that plan is also simpler, and the ones outlined by Biden and Harris are more difficult to explain during a national television debate, when the amount of time candidates have to respond to questions is limited.

“A pure Medicare-for-all plan is much easier to describe than these complicated plans that try to thread the political needle,” said Larry Levitt, a health policy expert at the Kaiser Family Foundation. “This was a huge problem for the Obama administration in trying to sell the Affordable Care Act.”

Allison Hoffman, professor of law at the University of Pennsylvania Law School and a senior fellow at the Leonard Davis Institute of Health Economics, said, “There’s definite discomfort. They both understand what they’re proposing, but I do feel like they’re both uneasy with the side-by-side comparison” with each other’s plan.

After getting into the race, Biden and Harris were delayed in introducing their health-care plans, with Biden initially talking vaguely about expanding the Affordable Care Act and Harris voicing support for Sanders’s Medicare-for-all legislation, though not committing to all of its details.

Since then, both candidates have released more-detailed policy plans outlining their preferred health-care proposals.

Biden has proposed expanding Obamacare by creating a government program that all Americans could purchase if they lacked health-care insurance or wanted to switch plans — a so-called public option.

By creating a new government insurer that competes with private insurance companies, Biden’s plan is intended to drive down private insurers’ costs while also creating a more affordable alternative. A similar idea was pushed as part of President Barack Obama’s Affordable Care Act but was ultimately abandoned amid industry opposition.

Harris had said she supported the Sanders Medicare-for-all plan but backed away from some of the more dramatic elements of his legislation. Earlier this week, Harris released a plan that aims to move all Americans into a Medicare program after 10 years but would allow private, and more tightly regulated, plans to continue offering insurance.

The candidates on Wednesday overlooked the nuances of their plans, limited by time and competing with eight other candidates on the presidential debate stage.

When Biden rolled out his health-care plan earlier this month, he said it would cover 97 percent of Americans — leaving out about 10 million Americans. Harris told Biden, “For a Democrat to be running for president with a plan that does not cover everyone, I think is without excuse.”

Biden retorted that his plan would cover everyone, despite the statistics in his own policy proposal. Biden’s plan promises that Americans will not pay more than 8.5 percent of their income in health-care costs — but that cost is unaffordable for most low-income Americans, said Hoffman, the Penn Law professor.

Harris faced her own difficult policy terrain, particularly over the impact of her plan on the more than 150 million Americans who have employer-sponsored insurance.

After Bennet said Harris’s plan would eliminate employer-sponsored care, Harris deflected and talked about how private plans would still be available under her proposal. That marked a contrast with Sanders and Warren, who have acknowledged their single-payer plan would lead people to switch to the public system.

“Senator Harris says she doesn’t ban private insurance, but all Americans would be getting their primary care through Medicare,” said Brian Riedl, a budget expert at the libertarian-leaning Manhattan Institute. “So how does that leave much room for an employer-provided system?”