Carter Alswinn Kieboom Bio
Carter Alswinn Kieboom is an American professional baseball third baseman who has played in Major League Baseball for the Washington Nationals and Los Angeles Angels. Born on September 3, 1997, in Marietta, Georgia, Kieboom was selected by the Washington Nationals in the first round of the 2016 MLB Draft. He made his major league debut in 2019 and has since appeared in parts of five MLB seasons while working through various injuries and roster moves throughout his professional career.
Early Life and Background
Kieboom grew up in Marietta, Georgia, where he attended George Walton Comprehensive High School. During his high school years, he established himself as a promising baseball talent, drawing attention from college programs across the country. His performance at the prep level earned him a commitment to continue his baseball career at the collegiate level.
After graduating from George Walton Comprehensive High School, Kieboom committed to attend Clemson University to play college baseball for the Clemson Tigers. However, his professional aspirations would take precedence as he entered the 2016 Major League Baseball Draft, where professional scouts had been tracking his development throughout his high school career.
Path to Professional Baseball
The Washington Nationals selected Kieboom in the first round of the 2016 MLB Draft, recognizing his potential as a future cornerstone infielder. On June 11, 2016, Kieboom announced he would sign with the Nationals, choosing to begin his professional career rather than attend Clemson University. He spent his first professional summer with the rookie-level Gulf Coast League Nationals, where he posted a batting average of .244 with four home runs and 25 RBIs in his inaugural professional season.
In 2017, Kieboom advanced to Single-A Hagerstown Suns and quickly demonstrated his hitting ability, posting a .333 batting average with six home runs and 20 RBIs before suffering a hamstring injury on May 12 that placed him on the disabled list. Despite the injury setback, he was named to the Northern Division All-Star team in the South Atlantic League. Both Baseball America and MLB Pipeline recognized his talent, listing him as the Nationals’ fourth-best prospect heading into the 2018 season.
The 2018 season marked a significant advancement in Kieboom’s development. Playing for the High-A Potomac Nationals, he earned Carolina League All-Star honors and delivered an impressive performance in the All-Star Game, hitting a home run while going 3-for-5 at the plate. He was promoted to Double-A Harrisburg Senators following the All-Star break and made an immediate impact, homering off Baltimore Orioles prospect Keegan Akin in his first game at the higher level on June 21. That same year, Kieboom represented Team USA in the All-Star Futures Game at Nationals Park, standing out as one of two Nationals minor league players selected for the event.
Carter Alswinn Kieboom Career
Washington Nationals (2019–2021, 2023)
Kieboom began the 2019 season with the Triple-A Fresno Grizzlies of the Pacific Coast League. On April 26, 2019, the Nationals purchased his contract and promoted him to the major league roster for a series against the San Diego Padres. He made his MLB debut that night and made an immediate impression by hitting a home run for his first major league hit. Kieboom appeared in 11 games with Washington during his debut campaign, compiling a .128 batting average with two home runs. The Nationals finished the 2019 season with a 93-69 record, clinching a wild card spot and ultimately winning the World Series over the Houston Astros. Kieboom did not participate in any postseason action during the championship run.
Following the departure of veteran third baseman Anthony Rendon after the 2019 season, Nationals manager Dave Martinez announced in January 2020 that Kieboom would transition to third base full time, with the expectation that he would step in as Rendon’s permanent replacement for the 2020 season. The abbreviated 2020 campaign saw Kieboom play in 33 games for Washington, hitting .202 with a .344 on-base percentage but managing no home runs and nine RBIs before his season ended early due to a left wrist contusion.
Kieboom appeared in 62 games during the 2021 season, his most extensive action with the Nationals, hitting .207 with six home runs. The 2022 season proved to be a significant setback when, on March 20, it was announced that he would miss four to six weeks while recovering from a flexor mass strain near his right elbow, placing him on the 60-day injured list the following day. Further examination revealed that Kieboom would require Tommy John surgery, causing him to miss the entire 2022 season.
He began the 2023 season in extended spring training before being activated by the Rochester Red Wings of Triple-A in May. Kieboom went on the injured list in June due to an oblique muscle injury but returned to the majors by hitting a home run in his first at-bat. In 26 games for Washington during his 2023 stint, he batted .207 with a .266 on-base percentage and .368 slugging percentage, adding four home runs and 11 RBIs. On March 13, 2024, Kieboom was removed from the 40-man roster and sent outright to Triple-A Rochester. He responded with a strong season, playing 91 games and slashing .265/.365/.386 with seven home runs and 42 RBIs before electing free agency following the campaign on November 4.
Los Angeles Angels (2025)
On December 6, 2024, Kieboom signed a minor league contract with the Los Angeles Angels organization. He reported to Triple-A Salt Lake Bees and delivered an outstanding 2025 minor league season, batting .319 with a .368 on-base percentage and .449 slugging percentage, adding nine home runs, 57 RBIs, and 11 stolen bases in 93 appearances. His performance earned a promotion to the major league roster on September 16, 2025. Kieboom appeared in three games for the Angels, going 2-for-8 at the plate with one RBI. Following the season, he was removed from the 40-man roster and sent outright to Salt Lake, subsequently rejecting the assignment and electing free agency.
Philadelphia Phillies (2026)
On January 13, 2026, Kieboom signed a minor league contract with the Cleveland Guardians. Less than three months later, on March 21, he was traded to the Philadelphia Phillies in exchange for cash considerations, continuing his journey through professional baseball organizations as he seeks another opportunity at the major league level.
Driving Style and Strengths
Kieboom has been recognized throughout his minor league career for his offensive capability and ability to make contact at the plate. His power-hitting potential was evident from his early professional seasons, as demonstrated by his All-Star Game performances and consistent home run production in the minors. His approach at the plate has shown patience, with on-base percentage numbers suggesting plate discipline. Defensively, he has primarily played third base while also seeing time at shortstop and second base during his development years.
Notable Events and Milestones
The most memorable moment of Kieboom’s career came during his MLB debut on April 26, 2019, when he homered for his first major league hit against the San Diego Padres, immediately announcing his arrival at the sport’s highest level. His selection to the 2018 All-Star Futures Game represented a significant milestone, showcasing him among the top prospects in all of baseball. His recovery from Tommy John surgery in 2022 demonstrated resilience as he worked to return to competitive form. The 2025 season with Salt Lake Bees marked a career resurgence at the Triple-A level, putting up his most productive minor league numbers.
Carter Alswinn Kieboom Career Wins
Across his professional career spanning parts of five MLB seasons, Kieboom has accumulated 12 home runs and 43 RBIs while posting a career batting average of .200. His minor league career has shown considerably more success, with consistently strong numbers at every level below the major leagues. The bulk of his professional experience has come at the Triple-A level, where he has demonstrated the ability to hit for average and power.
Major League Baseball Highlights
In MLB play, Kieboom’s most productive stretch came during his partial seasons with the Washington Nationals from 2019 to 2023. His debut home run on April 26, 2019, remains one of the most notable moments of his major league career. The 2021 season saw him play his most games at the MLB level with 62 appearances, during which he hit six home runs. His brief 2025 stint with the Angels saw limited action, though his overall career MLB totals reflect 12 home runs and 43 RBIs across his appearances.
Minor League Highlights
Kieboom has enjoyed considerable success in the minor leagues throughout his career. His 2017 season with Hagerstown was cut short by injury but showed exceptional promise with a .333 batting average. His 2018 campaign included Carolina League All-Star honors and a Futures Game appearance. The 2025 season with Salt Lake Bees represented his strongest professional performance, as he posted a .319 batting average with nine home runs and 57 RBIs in 93 games, establishing himself as one of the top performers at the Triple-A level that season.
| Level | Games | Batting Average | Home Runs | RBI |
|---|---|---|---|---|
| MLB Career | 132 | .200 | 12 | 43 |
| Triple-A Salt Lake (2025) | 93 | .319 | 9 | 57 |
Carter Alswinn Kieboom Family
Family Background and Baseball Lineage
Carter Kieboom comes from a family with deep baseball roots. His brother, Spencer Kieboom, also played professional baseball and appeared with the Washington Nationals during the 2018 season, making the Kieboom household one with direct representation in Major League Baseball. Their father was born in the Netherlands and played baseball on the Dutch junior national team before competing in the Honkbal Hoofdklasse, which is the top level of professional baseball in the Netherlands. This international baseball heritage provided Carter and Spencer with unique perspectives on the sport from an early age.
Personal Life
Growing up in Marietta, Georgia, Carter Kieboom benefited from a family environment that valued and understood competitive baseball. His brother’s path to the majors provided both inspiration and guidance as Carter navigated his own professional journey. The family’s Dutch connection through their father added an international dimension to their baseball background, distinguishing them from many other American baseball families.
2025 Season Performance
The 2025 season represented a significant turnaround in Kieboom’s professional career after several challenging years. After beginning the year in the Angels minor league system with Triple-A Salt Lake Bees, Kieboom delivered the best statistical performance of his professional career. His .319 batting average, combined with nine home runs, 57 RBIs, and 11 stolen bases in 93 appearances, demonstrated his ability to impact games in multiple facets. The power and average numbers both represented significant improvements over his previous minor league campaigns.
Kieboom’s strong minor league performance earned him a September call-up to the Los Angeles Angels major league roster on September 16, 2025. While his sample size of three games was limited, the opportunity marked his return to MLB action following an extended period of rehab and minor league seasoning. His ability to produce at the Triple-A level consistently positioned him for another chance at the majors.
Following the conclusion of the 2025 season, Kieboom was removed from the Angels’ 40-man roster and sent outright to Salt Lake. After rejecting the assignment, he elected free agency, ultimately signing with the Cleveland Guardians in January 2026 before being traded to the Philadelphia Phillies. His continued movement through organizations reflects the competitive nature of earning a permanent spot on a major league roster, though his 2025 performance provided evidence that he remains capable of contributing at the highest level when given the opportunity.