The Congressional Budget Office projects millions of workers will leave employer-sponsored health plans over the next decade because of ObamaCare.

Some will opt to go on Medicaid, but others will be kicked off their company plans by employers who decide not to offer coverage anymore, according to a new CBO report titled,  “Federal Subsidies for Health Insurance Coverage for People Under Age 65: 2016 to 2026.”

The GOP committee chairmen issued subpoenas for Health and Human Services (HHS) documents related the “Basic Health Program,” which they say the administration is unconstitutionally funding despite a lack of appropriation from Congress.

Republicans say the Obama administration is paying out these funds for the program even though Congress has not appropriated the money. The administration argues that it already has a permanent appropriation under the Affordable Care Act, but Republicans say that permanent appropriation was only for the law’s tax credits, not for the Basic Health Program.

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.

The justices heard oral arguments in the case just last week. Now they are asking the parties to address how employees would obtain contraceptive coverage through their employer’s insurance companies without any involvement from the employer, including notifying the government, their insurer, or third-party administrator of their objection.

The parties have the opportunity to spell out for the Supreme Court how such a system could work without controlling the Little Sisters’ and other employers’ insurance plans.

According to a Blue Cross Blue Shield Association report, people who enrolled in health insurance through the ACA appear to be sick than expected. People who enrolled in individual health insurance plans after 2014 were less healthy and used more healthcare in 2014 and 2015 than those who were already enrolled in individual plans and those who receive insurance through their employer.

The report isn’t without its shortcomings. It looked only at BCBS plans, not the entire universe of Obamacare insurers. But that’s still a sizable sample. BCBS companies participate in the exchanges more than any other insurer.