The move reunites Martin with Bucks first-year coach Jason Kidd after they teamed up together in New Jersey -- with both on the floor -- to lead the Nets to consecutive trips to the NBA Finals in 2002 and 2003.
Players can sign two 10-day contracts before a team must commit to sign them for the rest of the season or let them go. The Bucks waived guard Nate Wolters to make room on the roster.
Martin, 37, signed two 10-day deals with the New York Knicks late in the 2012-13 season and played well enough to finish that season with New York and then earn a deal for the 2013-14 season.
The former No. 1 overall pick in the 2000 NBA draft has averaged 12.5 points and 6.9 rebounds in 14 seasons. He auditioned for the Bucks last week and is expected to help them try to fill the frontcourt void left by the ongoing absence of center Larry Sanders, who has returned to the team this week but says he is working on his "psyche" and "physical health" after unspecified personal issues recently.
"I'm trying to get to the root of a lot of issues and get them corrected," Sanders told local reporters Tuesday. "Without getting them corrected, I don't think basketball is something I could do."
Sanders is the Bucks' starting center and defensive anchor as well as the club's highest-paid player. He's in the the first year of a four-year, $44 million extension and is averaging 7.3 points and 6.1 rebounds in 27 games. Milwaukee is 5-3 without Sanders, who said Tuesday that there is no timetable yet for his return to the court.
"I'll have to go with [the team's] recommendations," Sanders said. "See what they say is best for my health going forward."
Said Kidd: "It hasn't affected us, and we just want Larry to get back as soon as possible. He makes us a better team."