The same change can be made to each word below to create new words:

TEST
ARMS
UGH
PINS
STING

HINT:
The change involves the same two letters.

Answers:

The letters LA, when properly placed, will change each word into a new one:

LATEST
ALARMS
LAUGH
PLAINS
LASTING

Credit: LA Times Crossword
March 29, 2009
Kathleen Fay O'Brien
LOS ANGELES CLIPPERS