As congressional Republicans push for a delay in the 2010 health law’s individual mandate, the Obama administration Tuesday announced final regulations implementing the requirement that most Americans have health insurance coverage by Jan. 1 or pay a fine.

The document from the Treasury Department and the Internal Revenue Service is in addition to regulations the Department of Health and Human Services published in late June.

The regulations specify nine categories of individuals who are exempt from the mandate, including people who can’t afford coverage or taxpayers whose income is so low they don’t have to file a tax return, according to a fact sheet from the agencies. People in jail or who are not in the country lawfully are also exempt, as are individuals who experience a coverage gap of three months or less.

When filing 2014 taxes in 2015, individuals must indicate on their returns if they have health insurance coverage and, if not, pay a fine. The individual penalty is the greater of $95 or 1 percent of income, rising to the greater of $695 or 2.5 percent of income, in 2016. The Congressional Budget Office estimates that less than 2 percent of Americans who don’t have health insurance will pay the fine.

In July, the Obama Administration delayed for one year a provision in the health law that employers with 50 or more workers offer coverage to employees or pay a fine. Republicans said that if the administration delayed the “employer mandate” for a year, individuals should also get a reprieve from the health law’s individual mandate set to begin next January. In July, the House of Representatives passed legislation to delay the individual mandate requirement for a year, but the measure is not expected to come to a vote in the Senate.

Tuesday’s announcement from Treasury and the IRS — along with the final individual mandate regulations that HHS issued in June — make it clear that the administration is moving ahead with implementing the individual mandate, which has become one of the law’s most politically explosive elements. House Republicans have tried to repeal or defund the law 40 times on the House floor and more votes are likely this fall.

Supporters of the law and many health care economists say that the requirement that most Americans have coverage or pay a fine is critical to making the law work as intended.

“The individual mandate is one of two lynchpins that make the Affordable Care Act work,” Washington state Insurance Commissioner Mike Kreidler said in a statement. “You simply cannot guarantee everyone coverage — regardless of their health status — without also requiring that everyone participate. The individual mandate guarantees personal responsibility. Without it, there’s nothing to prevent people from only buying health insurance when they need it — which is similar to allowing people to buy homeowners insurance when their house is on fire.”

America’s Health Insurance Plans, a trade group representing health insurers, wants the health law’s tax on health insurance plans repealed but supports the individual mandate.

“There is broad agreement that requiring health plans to cover everyone, including those with pre-existing conditions, cannot work without an individual mandate,” the group said in a statement. “By requiring all Americans to obtain health coverage, the risk pool becomes large enough to account for the sickest Americans, without the adverse effect of skyrocketing premiums.”