WASHINGTON — Warding off the specter of election-year health insurance cancellations, the Obama administration Wednesday announced a two-year extension for individual policies that don’t meet requirements of the new health care law.

The decision helps defuse a political problem for Democrats in tough re-election battles this fall, especially for senators who in 2010 stood with President Barack Obama and voted to pass his health overhaul.

The extension was part of a major package of regulations that sets ground rules for 2015, the second year of government-subsidized health insurance markets under Obama’s law — and the first year that larger employers will face a requirement to provide coverage.

Hundreds of pages of provisions affecting insurers, employers and consumers were issued by the Treasury Department and the Department of Health and Human Services.

The cancellation last fall of at least 4.7 million individual policies was one of the most damaging issues in the transition to a new insurance system under Obama’s law. The wave of cancellations hit around the time that the new HealthCare.gov website was overwhelmed with technical problems that kept many consumers from signing up for coverage. It contradicted Obama’s promise that you can keep your insurance plan if you like it.

The latest extension would be valid for policies issued up to Oct. 1, 2016. It builds on an earlier reprieve issued by the White House.

It’s not clear how many people will actually be affected by the two-year extension on policies. The administration cites a congressional estimate of 1.5 million people.