Still, BP has yet to close the books on the tragedy, and the cost for the company could climb much higher.
For one thing, the U.S. government and the Gulf states are still seeking billions of dollars in civil penalties against BP over the environmental damage under such laws as the Clean Water Act.
Also, a federal judge in New Orleans is deciding whether to approve an estimated $7.8 billion settlement between BP and more than 100,000 businesses and individuals who say they were harmed by the spill. They include fishermen, charter boat captains, restaurants, hotels and property owners.
The Deepwater Horizon rig blew up 50 miles off Louisiana on April 20, 2010, in an explosion that investigators blamed on time-saving, cost-cutting decisions by BP and its drilling partners in cementing the well shaft.
Following several failed attempts that introduced the American public to such industry terms as "top kill" and "junk shot," BP finally capped the well on the sea floor after more than 85 days.
By then, the well had spewed an estimated 172 million gallons of crude into the Gulf, fouling marshes and beaches, killing wildlife and closing vast areas to fishing.
BP will plead guilty to 11 felony counts of misconduct or neglect of a vessel's officers, one felony count of obstruction of Congress and one misdemeanor count each under the Migratory Bird Treaty Act and the Clean Water Act. The workers' deaths were prosecuted under a federal law that protects seamen.
Nelda Winslette's grandson Adam Weise of Yorktown, Texas, was killed in the blast. She said somebody needs to be held accountable.
"It just bothers me so bad when I see the commercials on TV and they brag about how the Gulf is back, but they never say anything about the 11 lives that were lost. They want us to forget about it, but they don't know what they've done to the families that lost someone," she said.
Sherri Revette, who lost her husband of 26 years, Dewey Revette, of State Line, Miss., said the indictments against the employees brought mixed emotions.
"I'm saddened, but I'm also happy at the same time that they will be prosecuted. I feel for them, of course. You never know what impact your actions will have on others," she said.
Frank Parker, a shrimper from Biloxi, Miss., said: "I just hope the money gets down to the people who need it."
Scientists warn that the spill's full effect on the Gulf food chain may not be known for years. But they have reported oil-coated coral reefs that were dying, and fish have been showing up in nets with lesions and illnesses that biologists fear could be oil-related. Oil churned up by storms could be washing up for years.
The spill exposed lax government oversight and led to a temporary ban on deep-water drilling while officials and the industry studied the risks and worked to make it safer. BP's environmentally friendly image was tarnished, and CEO Tony Hayward stepped down after some gaffes that included lamenting at the height of the crisis: "I'd like my life back."
The cost of the spill far surpassed that of the Exxon Valdez disaster in 1989. Exxon ultimately settled with the government for $1 billion, which would be about $1.8 billion today.
The government and plaintiffs' attorneys have also sued Transocean Ltd., the rig's owner, and cement contractor Halliburton, but a string of pretrial rulings by a federal judge undermined BP's strategy of pinning blame on them.
Associated Press writers Pete Yost in Washington, Kevin McGill in New Orleans and Holbrook Mohr in Jackson, Miss., contributed to this story.