Eldine Baptiste took over for the tour of Sri Lanka which concludes with a Twenty20 match on Wednesday.
Sri Lanka won both tests and all three ODI internationals on the tour.
The West Indies Cricket Board (WICB) said in a statement that Simmons' reinstatement involved him receiving a letter of reprimand and making a public apology.
"I regret my public outburst during a press conference...and the revelation of the vote that took place at the selection meeting," said Simmons in an audio apology released by the WICB.
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"I extend a public apology to all whom I may have offended. I have personally apologised to my fellow selectors and the WICB and now do so again publicly.
"I am looking forward to putting this behind me and doing the job I enjoy with the West Indies' senior men's teams," said Simmons.
Former West Indies test batsman and Ireland coach Simmons took charge in March and led them to a 1-1 three-test series draw at home against England before suffering a 2-0 series defeat by Australia in the Caribbean.
(Reporting by Simon Evans; Editing by Tony Jimenez)
