Plan for the moment is:
144 to 150 this year
152 in 2023
156 per year for 2023 to 2028
LM could (theoretically) build more. From memory, there is line capability for better than 180 per year and output could probably top 200 aircraft per year if necessary.
The main problems are insufficient numbers with the test/simulator environment (slowing pre-delivery testing down of each aircraft), delays at Pratt & Whitney with engine deliveries and the mess that was caused when Turkey was ejected from the programme (which meant some key supplier agreements had to be torn up and re-tendered elsewhere).
Also the F35B and F35C are slowing things down too. The B takes 25-35% more man hours to build than the A, and then 50% more manhours for rework and rectification. The C takes 40-50% more manhours to build, and about 250% more manhours for rework and rectification.
LM built and reworked 189 F35As in 2020 and 2021, taking just under 900,000 man hours (average of 47,590 per aircraft). In the same time, it built/reworked 38 F35Bs taking just over 242,000 man hours (63,770 per aircraft) and 17 F35Cs taking just under 140,000 man hours (82,275 per aircraft).
Put another way, if LM had been building just As, it theoretically could have built 80 aircraft instead of 55 Bs and Cs. Of course, that leaves the Navy and the MC sweet out of luck though.