As reported before the season, the first five races of 2023 would see changes to the DRS zones, either extensions or reductions, in order to better balance overtaking.
In Miami the first two of three DRS zones have had their activation points moved further up the road.
The first DRS activation point on the flat-out run to Turn 11 has been pushed back from 30m after Turn 9 to 105m after the corner, reducing the DRS zone by 75 metres.
The second DRS zone on the back straight has also been shortened by 75 metres and now starts 525m after Turn 16 instead of 450m.
The final DRS zone onto the short start/finish straight, which has had a negligible effect on overtaking anyway, has been left untouched.
The tweaks have been made on a circuit-by-circuit basis and are therefore not related to the DRS reduction at last weekend's Azerbaijan GP, where the main straight's DRS zone was shortened by 100 metres.
But following a largely processional inaugural Miami GP last year, the shortened zones are likely to raise eyebrows.
On Sunday the Baku City Circuit produced a tepid race at which overtaking proved nearly impossible, and several drivers questioned why the DRS zone had been reduced when overtaking in 2023 turns out to be more difficult than the year before due to the extra downforce teams have added to their cars.
After being unable to overtake rivals in Baku, Mercedes' Lewis Hamilton said: "They shortened the DRS this year down the straight, I don't quite know why they did that. We've always had great racing where the DRS was.
"By the time you switched the DRS on, it was too late. Was there a lot of overtaking today? Well, there you go."
When McLaren driver Lando Norris was asked if Baku's shorter DRS zone made sense, the Briton added: "No, none. All the drivers questioned it in the drivers' briefing."
The Miami International Autodrome, which loops around the Miami Dolphins' Hard Rock Stadium, has also been fully repaved for this year.
Its original surface received critical reviews from the drivers last year and was deemed to be a factor in the lack of action during the race.
In addition, Turn 15 has received a minor lay-out tweak, and the run-off areas at Turns 1, 4, 7 and 11 have been reduced and the barriers re-aligned. The walls have also been tweaked between Turn 13 and 14.
