Federal employees are feeling a bit more satisfied this holiday season, a survey from The Partnership for Public Service showed, even after four years of humbug sentiments.

The nonpartisan nonprofit released its annual "Best Places to Work in the Federal Government," on Dec. 8, showing a 58.1 out of 100 increase in employee satisfaction in 2015, jumping 1.2 points from last year's score.

"The employee voice is one of the most powerful tools that federal leaders have to understand their organizations," said Max Stier, president and CEO of the Partnership for Public Service, in a statement. "The Best Places to Work in the Federal Government data can be used to increase employee commitment and improve performance as agencies strive to better serve the American public."

Related: Read the report.

The Partnership and Deloitte surveyed more than 433,000 federal employees across 391 agencies to gauge the best agencies to in the government to work for. For the fourth year in-a-row, NASA led large agencies in job satisfaction, scoring 76.1 out of 100.

The intelligence community scored second at 67.1, followed by the Department of Justice at 66.3. The Federal Deposit Insurance Corporation led all mid-size agencies with a score of 81.1, followed closely by the Peace Corps.

The Federal Mediation and Conciliation Service took top honors to small agency satisfaction while the top agency subcomponent was the Tennessee Valley Authority's inspector general's office.

Seventy percent of the federal agencies saw employee satisfaction scores increase in 2015, up from 43.1 percent in 2014 and 24 percent in 2013, as the federal government emerged from the effects for the 2013 shutdown.

The Department of Labor scored the most improvement in large agencies, jumping 4.4 points to make it the eighth best place to work in its category. The Department of Housing and Urban Development jumped eight points to move it to the 21st best mid-size agency to work.

Additionally, for the first time, the survey grouped 75 agencies by six mission areas to get a sense of the best organizations in law enforcement, public health, national security, oversight, energy and environment and financial regulation. The FBI led law enforcement agencies with a score of 69.9 while the Secret Service lagged to a score of 33.4.

The survey showed that federal employees are seeing more satisfaction from their work, as categories like effective leadership rose 1.4 points in 2015. Overall this year's gains stopped a slide in satisfaction and commitment that saw scores fall from a peak of 65 points in 2010 to 56.9 points in 2014.

National Treasury Employees Union president Tony Reardon was not impressed, noting that spending cuts, workforce reductions in the IRS and other agencies and low-or-no pay raises have dampened spirits for federal employees.

"The overall satisfaction score may be up slightly, but make no mistake, federal employee morale remains low," Reardon said in a statement. "This is not surprising when federal employees face a barrage of unfair attacks from some in Congress on health care, retirement and workplace rights, inadequate pay raises that won't cover rising costs and the recurring possibility of yet another government shutdown."

Federal employee satisfaction still lags behind the private sector, which scored 76.7.