Insurers have begun to propose big premium increases for coverage next year under the 2010 health law, as some struggle to make money in a market where their costs have soared.

The companies also have detailed the challenges in their Affordable Care Act business in a round of earnings releases, the most recent of which came on Wednesday when Humana Inc. said it made a slim profit on individual plans in the first quarter, not including some administrative costs, but still expects a loss for the full year. The Louisville, Ky.-based insurer created a special reserve fund at the end of last year to account for some expected losses on its individual plans in 2016.

. . .

Among the most hotly debated of the issues Hillary Clinton and Bernie Sanders have taken on in the Democratic primary contest is how best to get to universal health insurance coverage. The former secretary of state favors incremental steps, and the senator calls for a single-payer system. That debate, and their focus on universal coverage as their goal, appears to have had a modest and perhaps surprising effect on attitudes toward the Affordable Care Act. The health-care law is an issue about which public attitudes seldom shift, yet the share of Democrats who want to expand the Affordable Care Act rose over the past year.

. . .

On Tuesday UnitedHealth Group reported a terrific first quarter, with strong performance across nearly all business lines. There was one exception: The conglomerate’s insurance exchange unit raised its projected Affordable Care Act losses for 2016 to $650 million from $525 million, after booking $475 million in red ink last year.

CEO Stephen Hemsley said ObamaCare’s instability, small market size and costly patient population “continue to suggest we cannot broadly serve it on an effective and sustained basis.” He said UnitedHealth will withdraw to “only a handful of states” in 2017.

Normally sedate insurance markets have been roiled by everything from the federally chartered co-op failures to enrollment well below projections. ObamaCare’s architecture also makes it economically rational for consumers to wait until they are about to incur major medical expenses to get covered, and administratively created “special enrollment periods” encourage such gaming.

. . .

Many health-insurance premiums rose again this year, sometimes by double digits. A lot of the increases were accompanied by higher deductibles as well. Insurers say the increases are justified because their costs have risen as more people with health problems have signed up for insurance in the wake of the Affordable Care Act.

Some policy experts see the higher out-of-pocket costs as a positive development. When patients have a bigger stake in the cost of their care, the argument goes, they can drive prices down by spurning providers and services that are overpriced and inefficient.

Others argue, however, that it’s unfair to put the responsibility for reducing health costs on patients—particularly those with lower incomes, for whom quality health care is increasingly out of reach.

. . .

The analysis, based on claims from 21 Blue Cross and Blue Shield insurers around the country, highlights a challenge the companies say they face covering the population that signed up for plans issued under the ACA, sold both on the law’s signature marketplaces and outside them.

A number of Blue Cross and Blue Shield insurers faced increasing financial losses in 2015 on their ACA business, and some have responded by raising rates or tweaking their approaches this year.

In a report, the Department of Health and Human Services said Monday that there are around two million low-income, uninsured people in those 20 states who have a mental illness or substance abuse disorder.

Medicaid has long been a joint federal-state program that offers near-free care to the very poor. Under the health law, Washington pays almost all of the costs of insuring people who have slightly higher incomes.

Opponents of expansion argue that neither states nor the federal government can afford to further swell the program, and that a shortage of providers to treat the newly insured poses an additional challenge in trying to enroll more people in it.

When federal lawmakers wrote the act overhauling the nation’s health-care system six years ago, they ruled out any possibility of extending health insurance to illegal immigrants.

Local officials where many of those immigrants live are treating them anyway.

A Wall Street Journal survey of the 25 U.S. counties with the largest unauthorized immigrant populations found that 20 of them have programs that pay for the low-income uninsured to have doctor visits, shots, prescription drugs, lab tests and surgeries at local providers. The services usually are inexpensive or free to participants, who must prove they live in the county but are told their immigration status doesn’t matter.

On Wednesday the Supreme Court will hear oral arguments in Little Sisters of the Poor v. Burwell, a landmark case challenging the Department of Health and Human Services contraceptive mandate under the Affordable Care Act.

It is common knowledge that the Catholic Church has taught the immorality of abortion and contraceptive use for millennia. Yet the regulations in question force our institutions to pay for insurance that covers abortifacients like Ella and Plan B, plus prescription contraceptives and surgical sterilizations.

The United States was founded on the concept of religious freedom. The First Amendment says clearly that “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof.”

The Supreme Court on March 23 will  weigh how far the government has to go to accommodate religiously affiliated employers that object to including contraception in workers’ insurance plans. The issues has been brewing since shortly after the Affordable Care Act was signed into law in 2010.

House v. Burwell is far from resolution, but this case’s path through the federal courts and the threat it could pose to the Affordable Care Act show continued vulnerabilities of the health-care law as well as the stakes of the 2016 election.

A Commonwealth Fund report published Thursday looks at a provision in the health-care law that is at issue in the case. To soften the impact of out-of-pocket costs under Obamacare, the law requires insurers to reduce certain payments for individuals whose incomes are up to 250% of the federal poverty level if they purchase a “silver” plan through one of the insurance marketplaces. The law also says that insurers are to be repaid for the discounts.