Clippard was traded on December 4, 2007, to the Washington Nationals for relief pitcher Jonathan Albaladejo.
The Nationals viewed him as a contender for a spot in the starting rotation.
However, he began the season with the Columbus Clippers, Washington's Class AAA affiliate.
He pitched his first game for the Nationals on June 9, 2008, after Odalis Pérez was placed on the 15-day disabled list.
He was optioned to the minor leagues after this start, but was given a second start a few days later, as Pérez was not yet ready to return.
The Nationals then optioned Clippard to Columbus after his second start, in which Clippard pitched to a 1–1 record and 4.35 ERA.
He was recalled later in June as Shawn Hill was placed on the disabled list.
He spent most of the season with Columbus, going 6–13 with a 4.66 ERA.
He tied Yorman Bazardo and Charlie Haeger for the most losses in the International League that season.

During spring training in 2009, the Nationals optioned Clippard to the Syracuse Chiefs, Washington's new Class AAA affiliate.
Despite starting six games with the Yankees in 2007 and two for the Nationals in 2008, he was converted to a relief pitcher for the 2009 campaign.
Nationals' pitching coach Steve McCatty told Clippard that his future was pitching in relief, because his pitch count tended to get too high in starts, and opposing batters hit Clippard well by the third time the lineup turned over in a game.
Clippard at first resisted the transition to the bullpen, but conversations with his father and agent, Casey Close, reassured him to continue pursuing his dream.
Clippard appeared in 20 games for Syracuse in 2009, posting a 4–1 record, 0.92 ERA, and 42 strikeouts in 39 innings.
Clippard pitched in 14 consecutive scoreless appearances before being promoted to the Nationals on June 21, 2009, replacing Kip Wells in the Nationals' bullpen.
Used sparingly in the first weeks after his promotion, he posted a 2.69 ERA through ​60 ¹⁄₃ innings, with 67 strikeouts.

Since 2010, Clippard has pitched exclusively out of the bullpen; primarily in the eighth inning.
That season, Clippard and Drew Storen served as setup pitchers to Matt Capps.
After pitching effectively in the first half of the season, Clippard and Capps earned the nickname "Clip and Save".
Clippard finished eighth in the National League in appearances, with 78.
He won eleven games on the season, which led the team.

In the first half of the 2011 season, Clippard had a 1–0 record and 1.73 ERA.
He struck out 63 batters and allowed only 26 hits in ​51 ¹⁄₃ innings pitched, and allowed only six of 32 inherited runners to score.
For his achievements, Clippard was selected to appear in the All-Star Game.
He earned the victory for the National League as the game's winning pitcher, despite not retiring a batter.
Adrián Beltré, the only batter Clippard faced, singled, but Hunter Pence threw out José Bautista at home plate, and the NL took the lead in the next inning.
Clippard finished the season with a 3–0 record, a 1.83 ERA, and 104 strikeouts in ​88 ¹⁄₃ innings pitched across 72 appearances.
He led the National League in win probability added.

Before the 2012 season, Clippard and the Nationals agreed to a one-year contract worth $1.65 million, avoiding salary arbitration.
Clippard became the de facto closer for the Nationals in the first half of the 2012 season.
After injuries to Storen and Brad Lidge, Henry Rodríguez became the closer, but Rodriguez lost the job to Clippard due to his struggles.
The Nationals kept Clippard as their closer even after Storen returned to the team.
He was named the Major League Baseball Delivery Man of the Month for his performance in June 2012, recording ten saves in ten opportunities, and allowing zero runs in ​11 ²⁄₃ innings pitched.

Clippard earned $4 million in 2013.
He had a 6–3 record with a 2.41 ERA and 73 strikeouts in 71 innings pitched.
Clippard and the Nationals agreed on a $5.875 million salary for the 2014 season.
He appeared in 20 of the Nationals' first 40 games, and struggled with poor command of his pitches.
His command improv
Clippard was traded on December 4, 2007, to the Washington Nationals for relief pitcher Jonathan Albaladejo. The Nationals viewed him as a contender for a spot in the starting rotation. However, he began the season with the Columbus Clippers, Washington's Class AAA affiliate. He pitched his first game for the Nationals on June 9, 2008, after Odalis Pérez was placed on the 15-day disabled list. He was optioned to the minor leagues after this start, but was given a second start a few days later, as Pérez was not yet ready to return. The Nationals then optioned Clippard to Columbus after his second start, in which Clippard pitched to a 1–1 record and 4.35 ERA. He was recalled later in June as Shawn Hill was placed on the disabled list. He spent most of the season with Columbus, going 6–13 with a 4.66 ERA. He tied Yorman Bazardo and Charlie Haeger for the most losses in the International League that season.
During spring training in 2009, the Nationals optioned Clippard to the Syracuse Chiefs, Washington's new Class AAA affiliate. Despite starting six games with the Yankees in 2007 and two for the Nationals in 2008, he was converted to a relief pitcher for the 2009 campaign. Nationals' pitching coach Steve McCatty told Clippard that his future was pitching in relief, because his pitch count tended to get too high in starts, and opposing batters hit Clippard well by the third time the lineup turned over in a game. Clippard at first resisted the transition to the bullpen, but conversations with his father and agent, Casey Close, reassured him to continue pursuing his dream. Clippard appeared in 20 games for Syracuse in 2009, posting a 4–1 record, 0.92 ERA, and 42 strikeouts in 39 innings. Clippard pitched in 14 consecutive scoreless appearances before being promoted to the Nationals on June 21, 2009, replacing Kip Wells in the Nationals' bullpen. Used sparingly in the first weeks after his promotion, he posted a 2.69 ERA through ​60 ¹⁄₃ innings, with 67 strikeouts.
Since 2010, Clippard has pitched exclusively out of the bullpen; primarily in the eighth inning. That season, Clippard and Drew Storen served as setup pitchers to Matt Capps. After pitching effectively in the first half of the season, Clippard and Capps earned the nickname "Clip and Save". Clippard finished eighth in the National League in appearances, with 78. He won eleven games on the season, which led the team.
In the first half of the 2011 season, Clippard had a 1–0 record and 1.73 ERA. He struck out 63 batters and allowed only 26 hits in ​51 ¹⁄₃ innings pitched, and allowed only six of 32 inherited runners to score. For his achievements, Clippard was selected to appear in the All-Star Game. He earned the victory for the National League as the game's winning pitcher, despite not retiring a batter. Adrián Beltré, the only batter Clippard faced, singled, but Hunter Pence threw out José Bautista at home plate, and the NL took the lead in the next inning. Clippard finished the season with a 3–0 record, a 1.83 ERA, and 104 strikeouts in ​88 ¹⁄₃ innings pitched across 72 appearances. He led the National League in win probability added.
Before the 2012 season, Clippard and the Nationals agreed to a one-year contract worth $1.65 million, avoiding salary arbitration. Clippard became the de facto closer for the Nationals in the first half of the 2012 season. After injuries to Storen and Brad Lidge, Henry Rodríguez became the closer, but Rodriguez lost the job to Clippard due to his struggles. The Nationals kept Clippard as their closer even after Storen returned to the team. He was named the Major League Baseball Delivery Man of the Month for his performance in June 2012, recording ten saves in ten opportunities, and allowing zero runs in ​11 ²⁄₃ innings pitched.
Clippard earned $4 million in 2013. He had a 6–3 record with a 2.41 ERA and 73 strikeouts in 71 innings pitched. Clippard and the Nationals agreed on a $5.875 million salary for the 2014 season. He appeared in 20 of the Nationals' first 40 games, and struggled with poor command of his pitches. His command improv
Tyler Clippard