He attended pre-draft visits and private workouts with multiple teams, including the Pittsburgh Steelers, Carolina Panthers, Seattle Seahawks, Detroit Lions, and Philadelphia Eagles.

[17] Head coach Bill O'Brien named Reid as a backup safety to start the regular season, behind starters Kareem Jackson and Tyrann Mathieu.

On September 9, 2018, Reid made his professional regular season debut in the Texans' season-opener at the New England Patriots and recorded one solo tackle and a pass deflection in a 27–20 loss.

In Week 8, he had nine combined tackles (five solo), a season-high two pass deflections, and had his second pick of the season on Brock Osweiler in the Texans' 42–23 loss to the Miami Dolphins.

He finished his rookie season in 2018 with a total of 88 combined tackles (70 solo), ten pass deflections, three interceptions, and one touchdown in 16 games and 12 starts.

[18] He successfully underwent surgery on his wrist during the offseason to repair what was described as mild wear and tear".Entering training camp, Reid was projected to be a starter at safety after they lost both Tyrann Mathieu and Kareem Jackson in free agency.

[19] Defensive coordinator Romeo Crennel decided to pair Reid and Tashaun Gipson were named the starting safeties to begin the regular season.

In Week 2 of the 2019 season against the Jacksonville Jaguars, Reid made four tackles and stopped running back Leonard Fournette on a two point conversion attempt as the Texans won 13–12.

[22] He finished his sophomore season with a total of 77 combined tackles (56 solo), five pass deflections, two interceptions, and a fumble recovery in 15 games and 15 starts.

On January 4, 2020, Reid started in his first postseason appearance and recorded seven combined tackles (four solo) in a 21–19 overtime victory against the Buffalo Bills in the NFC Wildcard Game.

Reid entered training camp and was expected to remain as the starting free safety under new defensive coordinator Lovie Smith.

[27] Head coach David Culley named Reid and Eric Murray the starting safeties to begin the regular season.

[34] The Kansas City Chiefs finished the 2022 NFL season atop the AFC West with a 14–3 record and earned a first round bye in the playoffs.

On January 29, 2023, Reid started in the AFC Championship Game and collected seven solo tackles and a pass deflection as the Chiefs defeated the Cincinnati Bengals 23–20.