Rachel Bilson and Autumn Reeser (Taylor Townsend!) had an O.C. reunion on Hart of Dixie's fourth season finale on Friday, Mar. 27 -- see the cute Instagram photo

From California to Alabama! Rachel Bilson reunited with her former The O.C. costar Autumn Reeser on Hart of Dixie's fourth season finale on Friday, Mar. 27.

Reeser guest-starred as Olivia Green, the new lawyer in town that takes over for George Tucker (Scott Porter). Just like fellow New Yorker Dr. Zoe Hart (Bilson), she has a hard time adjusting to Bluebell.

While on set in September, Reeser posted an adorable WhoSay photo of the costars reuniting. "Love this girl, such a pleasure to work w/ her again!!" she captioned. "A mini #OC reunion on the finale ep of @CWHartofDixie."

The following month, she also ran into her O.C. onscreen boyfriend Ben McKenzie, who played rugged Ryan Atwood. "All right, OC fans, here ya go," she wrote on Oct. 12. "Backstage at @ThrillingAdv in Brooklyn :) #nyc @ben_mckenzie #TAH #theOC."

All right, OC fans, here ya go... Backstage at @ThrillingAdv in Brooklyn :) #nyc @ben_mckenzie #TAH #theOC

A photo posted by Autumn Reeser (@autumn_reeser) on Oct 11, 2014 at 10:16pm PDT

Bilson played Summer Roberts on the Josh Schwartz-created teen drama The O.C. After plenty of Sandy Cohen bagel mornings and laundry loads of Ryan's white tank tops, Reeser joined as uptight (and very perky!) Taylor Townsend in the third season.

The O.C. ran for four seasons from 2003 to 2007. It also starred Adam Brody, Peter Gallagher, Kelly Rowan, Mischa Barton, Melinda Clarke, Tate Donovan, and Chris Carmack.

Bilson and Reeser have both become moms since saying goodbye to Ryan Atwood, Seth Cohen, and the rest of the gang. Us Weekly broke news in November that Bilson welcomed daughter Briar Rose with boyfriend Hayden Christensen. Reeser shares sons Finneus James, 3, and Dashiell Ford, 16 months, with estranged husband Jesse Warren. The Entourage actress filed for divorce in November.