LKA cost is included in the yearly MOC fees you pay, so you dont have to pay extra when its time to take it. If you want to do the 10-year exam, it is $700, separate from the yearly MOC fees. If you are due this year, pick which of the two you want to do. The only difference I know between CME and MOC is that CME is to maintain licensing and MOC is to maintain board certification. You have to do 1 MOC activity every 2 years to be considered to be actively participating in MOC, and then total 100 MOC points every 5 years to maintain board certification. What happens if you dont do a MOC activity every 2 years, I dont exactly know, but if you don't get the 100 points, then I assume you lose certification. You can often convert CME credits to MOC credits to submit them to ABIM. For example, if you do all your CME as UpToDate searches or attend a national conference (e.g., ACP), after you redeem your CME credits, you can go back in and "convert" them to MOC points- this is what I did and it was super easy to hit 100 points within 1 year.