Magnussen was handed three 10-second time additions penalties for repeatedly leaving the track and gaining advantages, plus one five-second penalty and a black-and-white warning flag for additional track limits abuse during the 19-lap contest around the Hard Rock Stadium on Saturday afternoon.
The Dane has also been summoned to the stewards ahead of grand prix qualifying for alleged unsportsmanlike behaviour.
His actions all took place against Hamilton while they ran adrift of Nico Hulkenberg, who went on to take two points for Haas with seventh place as Hamilton was delayed by Magnussen’s actions.
These included cutting the track’s tight chicane and twice going off track while fighting Hamilton closely – at one point barging into the Mercedes’ right-hand side.
“All the penalties were well deserved,” Magnussen told Sky Sports F1 post-race. “No doubt about it.
“But I had to play the game again. I was in a very good position behind Nico there. At the beginning of the race I gained a lot positions, was up in P8 and protecting well from Lewis because I had DRS from Nico and had good pace.
“But then Nico cut the chicane and I lost the DRS [on lap six in an incident that was not investigated].
“Nico could’ve given that back to give me the DRS to protect because then we would’ve easily been P7-P8.
“Instead, I was really vulnerable to Lewis [and we] started fighting like crazy.”
Magnussen also said he had to drive “to create the gap like I did in Jeddah” – where he was twice penalised during his efforts to hold up the cars of Haas’s midfield rivals as Hulkenberg escaped ahead to finish 10th.
“I started using these stupid tactics, which I don’t like doing,” he added. “But, at the end of the day, I did my job as a team player.
“Nico scored his points because I got that gap for him. Lewis and Tsunoda couldn’t catch him. Not the way I like to go racing, at all, but [was] what I had to do today.”
Magnussen eventually allowed Hamilton to pass by, after their Turn 11 clash on lap 14 that had meant Tsunoda’s RB slipped ahead of the Mercedes.
Hamilton would later repass Tsunoda on the final lap but lost the sprint race’s final point as he was hit with a post-race penalty for speeding in the pitlane during the early safety car period and so fell to 16th.
Magnussen currently has five penalty points on his license following his collision with Yuki Tsunoda in the Chinese GP.
If he were to be handed two points for each incident in the Miami sprint, he would be on 13 points and facing a race ban as the threshold for such a sanction is 12.
Autosport has approached the FIA for clarification on where Magnussen’s penalty points total now stands.