An agent's list

Agents tend to specialise in a particular genre: if your work is outside that genre, then you won't fit their list because they don't know any editors or publishers who publish that genre, or know anything about the books which have already been published in that genre so might not know whether something's been done before, or if something's effective in its genre.

So, they don't change their lists every few months and suddenly become open to new genres or styles: they just don't have the expertise or contacts to work effectively within your genre.

When an agent says a book doesn't fit her list, what she means is that she doesn't represent the genre or she doesn't know editors who buy books like yours. For example, if you don't research agents, you might send your YA paranormal query to an agent who only represents nonfiction or children's picture books.

A lot of agents also seem to accept queries in more genres than they actually represent; I think they do this so they won't miss out on a slam-dunk bestseller that's a little out of their wheelhouse. But your odds are going to be incrementally better if you find out what agents have sold books like yours.

Also, "not fitting the list" is likely to be form language, the excuse the agent gives to everyone she rejects. When the agent says your book doesn't fit her list, she does not mean "not now, but maybe later." This agent does not want to represent your book. Move on to other prospects.

When an a gent says your work doesn't fit her list, she's almost always say, "I don't want to represent this book." Don't try to read more into it.

Besides, in the sense you mean, an agent almost never changes her list.

It's just another way of saying no.

There is no list. I mean, the agent has their preferred genres, but there's no set number of authors they take on and that's it. It's a form rejection just like so many others.

Agree with Jamesaritchie and scarletpeaches. I always took it as a polite way of saying no.

"Doesn't fit my list" is a form rejection phrase.

It just means no.