Sandy was the most destructive storm in the US since Hurricane Katrina in 2005.
On Monday, historical immigration landmark Ellis Island reopened for the first time since the storm flooded low-lying areas in New York City.
But many communities are still struggling to rebuild amid complaints emergency funds have failed to reach the hardest-hit.
Still suffering
As of August, just under a quarter of the $48bn (£30bn) earmarked for rebuilding had been committed to local governments, according to Reuters news agency.
Federal officials have unveiled plans for a second round of disaster relief amounting to $5bn for five states and New York City, and they pledged that the pace of spending would pick up after a slow start.
"In year one, we all agreed the aid flowed too slowly," Senator Chuck Schumer, a New York Democrat, told reporters.
"The second year will be a lot better. The spigot is now open."
The BBC's Nick Bryant says the shorelines of New Jersey and New York still bear deep scars from Sandy, with empty lots where family and vacation homes used to stand, and businesses are closed down and boarded up.
Many owners are still battling to receive pay-outs from their insurance companies, while others are still waiting to find out whether they will receive compensation from the government for wrecked properties that are now uninhabitable.
"It is going to take years to rebuild," resident Aimam Youssef, who lost his home in Midland Beach, Staten Island, told the BBC.
"We should not be suffering like this after one year, we should not."
Almost two-thirds of the people who applied for federal disaster aid have not received any, our correspondent says.
In New York City, as work repairing the last subway line to be damaged by flooding continues, transit officials were offering free subway rides on Tuesday from hard-hit areas of the Rockaways and Howard Beach.Meanwhile, homes in Oakwood Beach, Staten Island, have been bought out under a state programme that promises to turn neighbourhoods wrecked by Superstorm Sandy into perpetual green space.
Events are being held to mark the anniversary of the storm, including a state-wide prayer service in New Jersey.
At least 117 deaths have been blamed on Sandy in the US, according to officials.
The storm also killed scores of people as it swept across the Caribbean.
Millions of people were forced to flee their homes.
