Urban legend. LMB has stated repeatedly that this is not so.

Huh. I wonder where I'd heard it from. I do think the first Cordelia book where she meets Aral has some Trek-ish elements. The Miles books, not so much.

I do think the first Cordelia book where she meets Aral has some Trek-ish elements

Like what?

It's been a while since I read the book, but Cordelia's planet (Beta Colony, I think?) is a tightly-regulated, technically-advanced society, which I could see as part of the Federation. Whereas Barrayar could be one of the more tradition-bound cultures Federations would clash with. Don't Cordelia and Aral get stranded somewhere and are forced to work together to get themselves out of the bind? Which is, on a very basic and generic sort of way, a plot we see a lot on Trek episodes. Like I said, I don't recall much detail about the book, but I remember not being too startled at the rumour about its alleged Trek-fic origin.

Here is the story, as told by LMB's best friend, with whom she was active in fandom:

One evening, as my infant son—who was born on a Friday the thirteenth—crawled over our feet, Lois told me of a story she'd been toying with: a Klingon officer and a redheaded Federation scientist (the latest in a long line of redheaded heroines) are stranded together on a planet resembling the African plains which Lois had recently toured. . . .

The years passed. Lois, too, gave birth to a son on a Friday the thirteenth. Then, one summer, soon after I'd made my first professional sale—proving that it was, amazingly, possible—she arrived at my house with the manuscript of her first novel. We sat until the wee hours of the morning crossing its t's and dotting its i's. Like a medieval alchemist she'd taken her germ of an idea, mixed in Ignatius Loyola, Winston Churchill, and Dumas's musketeer Athos (as portrayed by Oliver Reed in the 1972 movie), and decanted Aral Vorkosigan.

Well, she did a heck of a job differentiating, then. It never would have occurred to me to think Klingon when reading about Barryar.

I guess that's why it's not regarded as fanfic.

Interview with R.A. McAvoy.

I'm giving someone on DW reading recs, and coming up astonished that she hasn't read Bujold. I'm like: you're a geek, right? Read Bujold!

Except I haven't read the Sharing Knife sequence, because another friend tells me it's pants.

I have not read Bujold.

It's not her best. I was reading it, but I forgot if I'd read the first two or just the first one and haven't cared enough to figure it out so I'm stalled on the series. I'm pretty sure I actually own the ones I've read so eventually I will find them/it and know for sure...