SAN JUAN, P.R. — Though hundreds of thousands of Puerto Ricans remain in the dark five months after a devastating hurricane trampled the island’s power grid, the federal government has begun to scale back the number of contractors it has working to get the lights back on.

The United States Army Corps of Engineers is in charge of the federal effort to repair the power grid on the island, where a Category 4 storm last fall knocked out electricity to every home and business. The corps gave major contracts to two companies, Fluor Corporation and PowerSecure, and coordinates their work with the efforts of the island’s government-run power utility, which has also hired contractors and brought in crews from mainland utilities.

At one point, there were a total of 6,200 workers repairing transmission and distribution lines across the island, about half of them working for the corps. Now that power has been restored to more than 1.1 million people, by the utility’s count — about 86 percent of the island’s customers — the corps said it would begin a “responsible drawdown” of its work force.

Nearly 1,000 power workers have left the island in the past two weeks, according to Twitter messages posted by the corps. Fluor still had 1,600 people in Puerto Rico as of Sunday, but its contract period is “nearing the end,” and PowerSecure is scheduled to wrap up work by April 7, the corps said.