No, that's not what the CBO said in January. What they did was compare their projections of enrollment in ESI under the ACA vs. what they think it would be in the absence of the ACA. They came up with these projections:
Employer-based coverage under the ACA
Year | 2010 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Enrollment (in millions) | 150 | 156 | 156 | 153 | 155 | 155 | 156 | 156 | 155 | 157 | 157 | 157 | 157 |
Employer-based coverage, no ACA
Year | 2010 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Enrollment (in millions) | 150 | 156 | 158 | 160 | 163 | 164 | 165 | 165 | 165 | 166 | 166 | 166 | 166 |
You'll note that neither scenario involves long-term losses.
The number of people with employer-based coverage continues to grow in either scenario, the difference is that it grows faster in the no-ACA world. In the world we live in, more people will shop for their own plans independent of their employer as we go forward. The number of people with employer-based insurance doesn't fall.
What those tables
do not show is "10 million employees will lose their employer healthcare plans" (the ones they have now).
(CBO's March 2015 update to these projections narrow the gap between these projections anyway).
Again, you're mischaracterizing what they've said. From the CBO's blog
Frequently Asked Questions About CBO’s Estimates of the Labor Market Effects of the Affordable Care Act
Voluntary reductions in the amount of labor offered are not the same as "losing a significant percentage of their hours of work."
That's the difference between the CBO's with-ACA/without-ACA estimates. There are now realistic alternatives to the employer-based coverage, which means in the future people will drift toward those alternatives. That's a natural, organic change over time, not the disruption or people being stripped of what they have that you've been implying.