By the numbers: Why millions go uninsured under Republicans' Obamacare alternative

(CNN) President Donald Trump and House Speaker Paul Ryan are pushing legislation that would repeal key aspects of the Affordable Care Act.

Changing the heath insurance marketplace under Obamacare is complicated business, and there is no universal agreement on how any legislation would affect coverage.

But the Congressional Budget Office, the nonpartisan scorekeeper on Capitol Hill, released its best guess in its official score of the legislation, and some of the numbers are quite large. Below are some key figures from the report. You can read the entire document here.

What would happen to the rate of uninsured?

14 million more people would be uninsured in 2018.

21 million more people would be uninsured by 2020.

24 million more people would be uninsured by 2026.

It's important to note these numbers represent the non-elderly population, since most Americans get Medicare after they turn 65. The rate of uninsured would rise drastically, both because the law would do away with the requirement that people either obtain insurance or pay a fine and, in the later years, because of changes to Medicaid rules and spending is capped, according to CBO.

What's the difference between the GOP plan and Obamacare?

52 million people would be uninsured under the Republican plan in 2026.

28 million people would be uninsured under Obamacare in 2026.

Why would the uninsured rate grow?

-- Without penalties that people pay under Obamacare, fewer would buy insurance.

-- Later, the uninsured rate would rise as federal funding shrinks and states change Medicaid rules.

Would the cost of premiums rise or fall under the GOP plan?

Average premium costs in the non-group individual market -- the Obamacare exchanges -- would go up 15% to 20% in 2018 and 2019.

Average premium costs for single policyholders would then go down 10% by 2026 compared to Obamacare.

But while average premiums would go down in those later years, the relief would not be universal. Premiums would go up for older Americans and down for younger Americans.

What would happen to premiums by age?

Average prices in the individual market would be:

20 percent to 25 percent lower for a 21-year-old.

8 percent to 10 percent lower for a 40-year-old.

20 percent to 25 percent higher for a 64-year-old.

What would happen to the federal budget deficit?

It would go down $337 billion by 2026. Why? The government would spend $1.2 trillion less under the Republican plan than under Obamacare, but it would take in $900 billion less in taxes.