Is it OK to install a new sink without puttin in a drain cleanout?

Yes, it just makes it easier. Make sure you do have a cleanout closeby.

There is one within 10 ft.

In the State of Massachusetts, it is illegal to install a new kitchen sink without installing a full-size cleanout under the sink! As noted above, not all states have this requirement!

Mark

GA requires one in the branch lines but not under the sink.

Anyone know about the requirements in CA

Milo's a CA plumber that pops in frequently. My guess is that CA requires one under the sink as they have some of the toughest codes in the nation!