PPA says that new, faster vesting schedule applies once a participant has an hour of service in any plan year after effective date for plan. Can someone confirm that this means that plan's old vesting schedule will still apply to any contributions made prior to effective date? Or am I reading this wrong?

© EFFECTIVE DATES.—
(1) IN GENERAL.—Except as provided in paragraphs (2) and (4), the amendments made by this
section shall apply to contributions for plan years beginning after December 31, 2006.


(paras 2 &4 are collective bargaining and ESOPs).

Note that this is what the law says; the plan sponsor may decide to accelerate vesting on all contributions for simplicity.

in other words, it is no different than what happened to matching contributions a few years ago.