FAJARDO, P.R. — Juan Jimenez squinted into the dark lobby of his bank early Friday, thinking about the paycheck sitting in his account, just behind the locked doors. If only he could get to it.

With power failures and communications outages still widespread nine days after Hurricane Maria, much of Puerto Rico has become a cash-only island for Mr. Jimenez and others who desperately need to buy food, gasoline and ice from stores that cannot run credit cards, take phone payments or process electronic government benefits.

“You’re broke even if you have money,” Mr. Jimenez, 40, said.

Fewer than half of Puerto Rico’s bank branches and cash machines are up and running, still crippled by diesel shortages, damaged roads and severed communications lines. Bank officials say they are struggling even to find employees who can get to work when there is no public transportation and gasoline is hard to find.

Across the island, people who have spent their last dollars on an $8 bag of ice or $15 for gasoline are waiting for hours outside banks and A.T.M.s in hopes of withdrawing as much money as possible.

The cash crunch offers a glimpse of how Puerto Rico’s struggling economy, in which unemployment stood at 10 percent even before the storm, has ground to a near standstill across much of the island, as people with $11 in their pockets and no clue when they will return to work or restart their businesses now spend their days waiting for hours under parasols and the searing sun for basic supplies.

As people wait, rumors swirl about cash shortages and strict limits on withdrawals — neither of which is true, banking officials said.

Zoime Alvarez, vice president of the Association of Banks of Puerto Rico, said there was enough cash on Puerto Rico and more arriving to meet what the New York Federal Reserve called “extraordinarily high demand.”

And banking officials said the $500 daily limit on A.T.M. withdrawals had not changed since the storm, though bank branches that were still offline were imposing $100 limits. About 90 banks and 200 A.T.M.s are working across the island, government officials said. But many are opening late and closing by 2 p.m. or 3 p.m.

“We have been getting shipments of money,” the governor, Ricardo A. Rosselló, said. “We want to make sure people get access to the money that they need immediately, and recognizing that we are in an emergency situation.”

Enyoliz Parrilla, 35, has been rationing her cash as if it were a finite supply of water in a lifeboat. She had about $40 left, and as she pushed her cart through a reopened supermarket, she added up the cost of bread and milk. She wanted to keep the bill to $25.