From November 2014 through the end of his 2018 contract, Lanier served as the first manager of the Ottawa Champions of the independent Can-Am League.

Due to the unpredictable winds at Candlestick Park, Mays used to position the infielders on how to play the ball.

[2] However, by the end of the season, Mays had made Lanier the infield captain for the Giants, in charge of taking a trip to the mound if a pitcher needed a break.

Following his playing career, Lanier managed in the minors and served as third base coach for the St. Louis Cardinals from 1981–85, including the 1982 World Series and 1985 National League champion teams.

[4] In 1986, he was named NL Manager of the Year by the BBWA and TSN for leading the Astros to their first Division title since 1980 and the best record (96-66) in team history up to that point, which greatly surpassed expectations from a team that had finished fourth the previous year and hadn't won 90 games since 1980.

[6] He utilized an aggressive strategy built on pitching and baserunning meant to mirror the Cardinal teams he had coached on.

While they finished eighth in runs scored for National League teams (654), the Astros had three players steal at least twenty bases.

They won ten of the 14 games after the All-Star break, which included five straight walk-off victories; they won 14 of their last 18 games to clinch the division title, which famously saw the division be clinched in the Astrodome on a no-hitter pitched by Scott on September 25.

[12] The Astros lost 26 of their last 37 games that year, and Lanier cited a dislocated finger injury suffered by starting catcher Alan Ashby as a key to their late fizzle.

As the team prepared to eat the post-game meal, take showers, and go home, they received word they were wanted back on the field.

[15] Astro owner John McMullen cited the need for a clean slate in firing Lanier.

He served as the bench coach for the Philadelphia Phillies under Nick Leyva for the 1990 and 1991 seasons before Levya was fired.

Lanier's mother died in a Christmas Eve car crash when Hal was six years old; his father later remarried.