The case I was brought in on in LA cost the client $800 to do the 14 year calculation (from their date of separation to current), and the delta on what Fidelity paid the alternate payee vs what they should have was almost $100k difference. The intended judgment was simply for AP to get a $400k from 14 years ago adjusted by gains/losses...Fidelity did their very quick method of allocating gains/losses which yielded $100k less to AP than what it should have been (because Fidelity improperly weighted the contributions in favor of P over that time period). I was brought in to show the court that the AP was not trying to reach over the fence and take what was not awarded to them, I showed everyone the AP did not receive as much as was intended by the court and parties 14 years prior. P agreed Fidelity's calculation was inaccurate and the amended QDRO was entered. I'm not implying this case will have a similar outcome but it's not that costly to update and in my opinion well worth the extra money to ensure accuracy. It can be much more costly to have to go back and fix everything if post-Fidelity calculation the AP (or the P) discovers things were not done as accurately as one would hope!