CBS unveiled a relatively stable primetime lineup to advertisers on Wednesday (May 20), a schedule featuring 18 returning shows to TV's most watched network.

Despite that high retention, plus the cancellation of shows that other networks would have considered hits (R.I.P. "The Unit," "Eleventh Hour" and "Without a Trace"), CBS is not above tinkering. Only one night on CBS' new schedule remains unchanged, with big moves including the shift of freshman hit "The Mentalist" to Thursdays.

The fall will see the addition of three new dramas and one new comedies. The dramas are led by the "NCIS" spinoff "NCIS: LA," which was already introduced as a two-episode backdoor pilot on the "NCIS" mothership. The network also welcomes "Moonlight" star Alex O'Loughlin back to primetime in the organ transplant drama "Three Rivers" and brings Julianna Margulies back to the small screen for "The Good Wife." The lone new comedy, "Accidentally on Purpose," features Jenna Elfman in her latest stab at sitcom relevancy. 

Perhaps the most interesting twist in CBS' schedule is the addition of "Medium," cancelled by NBC on Tuesday and transplanted to Friday nights between "Ghost Whisperer" and "Numb3rs" today. The Canadian drama "Flashpoint" is still in the mix for a possible return, though maybe not until next summer.

Let's look at the rest of the week:

On Mondays, CBS has split up its 8 p.m. comedy block, returning "How I Met Your Mother" to 8 p.m. as a lead-in for "Accidentally on Purpose." "Big Bang Theory" will move to 9:30, where it can feed off "Two and a Half Men."  "CSI: Miami" isn't going anywhere.

"NCIS" will lead into its spinoff on Tuesday, with "The Good Wife" coming in at 10 p.m, while Wednesday will be untouched, with "The New Adventures of Old Christine," "Gary Unmarried," "Criminal Minds" and "CSI: NY."

Thursday is getting a boost with "Survivor" and "CSI: Crime Scene Investigation" remaining in place, but "The Mentalist" taking over at 10 p.m. "The Mentalist" has actually be outperforming "CSI" in recent weeks, so this positioning may elevate the older show as much as the new addition.

Fridays we've already mentioned and Saturdays are irrelevant, which leaves Sundays. "60 Minutes" and "The Amazing Race" will remain in place, leading into "Three Rivers" at 9 p.m. "Cold Case," one of CBS' lone renewed bubble dramas, goes to 10 p.m. 

For midseason, the network also has the return of "Rules of Engagement," the new dramas "Miami Trauma" and "The Bridge," plus the unscripted "Arranged Marriage" and "Undercover Boss."

 

CBS' 2009-2010 PRIMETIME SCHEDULE

MONDAY
8:00 p.m. "How I Met Your Mother"
8:30 p.m. "Accidentally On Purpose"
9:00 p.m. "Two and a Half Men"
9:30 p.m. "The Big Bang Theory"
10:00 p.m. "CSI Miami"

TUESDAY
8:00 p.m. "NCIS"
9:00 p.m. "NCIS: Los Angeles"
10:00 p.m. "The Good Wife"

WEDNESDAY
8:00 p.m. "Old Christine"
8:30 p.m. "30: Gary Unmarried"
9:00 p.m. "Criminal Minds"
10:00 p.m. "CSI:NY"

THURSDAY
8:00 p.m. "Survivor"
9:00 p.m. "CSI: Crime Scene Investigation"
10:00 p.m."The Mentalist"

FRIDAY

8:00 p.m. "Ghost Whisperer"
9:00 p.m. "Medium"
10:00 p.m."Numb3rs"

SATURDAY
8:00 p.m. Crime Drama
9:00 p.m. Crime Drama
10:00 p.m."48:00 Hours"

SUNDAY
7:00 p.m. "60 Minutes"
8:00 p.m. "The Amazing Race"
9:00 p.m. "Three Rivers"
10:00 p.m. "Cold Case"

MID-SEASON – "Miami Trauma," "The Bridge," "Undercover Boss," "Arranged Marriage," "Rules of Engagement"