The most common and most likely answer to this crossword clue is the 8 letter word REINSURE
I've seen this crossword clue in The Guardian
R
E
I
N
S
U
R
E
Buddy explains!

The straight part
We know that "Maintain the same policy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case maintain the same policy = reinsure.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does REINSURE mean?
REINSURE verb- To insure again (extending or replacing prior insurance).
- To place insurance on the contract that insures something (allowing the insurer to offset risk in the same way the insuree did).