Schwab) to name the three that I have accounts with. There's stuff about having to specify in writing in advance and all that, and if you ever sold some of a particular fund's assets and accepted the default average cost method, then you can't do the specific share identification thing on that fund in the future and all that. I haven't read the rules lately, but nothing I've seen has made it look like they've made it easier.
Nothing like what it should be -- check a little box for specific share identification -- and it pops up a window showing the various lots and the prices they were bought for with checkboxes next to each one that you can click to indicate you want to sell which lots -- no, nothing like that. Dunno why not, but they say life sucks and then you die.
Just a fair warning to anyone who thinks, "gee, I'm going to sell some shares today and use specific identification", nope, its going to take a lot longer and careful attention to all the rules. Unless you've done it before and got it all figured out, and have the "in advance, in writing thing" included in your time frame.
So far I haven't tried to use it -- basically I do my reallocations within IRAs so that capital gains aren't a factor. And I have a buffer intermediate bond fund in a regular account for when I need more money for my checking account, or, conversely, to invest surplus money from my checking account (so yes, selling from that bond fund will incur some capital gains, but it's minor compared to selling shares from a long-held equity fund).