A lot of vagueness in this thread.

Generally, there are three bases for entering a Star Alliance lounge on a Star Alliance international flight:

1. Star Alliance Gold member;

2. Traveling in business or first class; and

3. Red Carpet/Presidents Club Membership.

#1 only applies when flying in economy class. Other than the ability to bring in a guest when flying in business class, Gold status is irrelevant when flying in first or business class.

#2 has nothing to do with status. You get in because of the class of service in which you fly.

#3: I have no idea, but assume you gain admission to another Star Alliance lounge based on that membership. Again, this only applies when flying in economy class.

If the Star Alliance carrier has not designated the lounge as a "Star Gold" lounge, you don't get in under #1 (e.g., the Thai Air "D-Pier" business class lounge, although the other Thai business class lounges at Bangkok are Star Gold lounges).

Under #2, you do get into the Thai Air "D-Pier" business class lounge when flying on UA because you are entering based on your class of service--not your Star Gold status.

I don't know about #3.

So, when posters state they did or did not get in, it would be helpful if they stated there were granted or denied entry based on #1, #2 or #3.