Hi Jessica,
While I'm retired from the museum field, we offered a 50% match on up to a 6% employee contribution. The employee must contribute to get the match.
When I was at the museum, there was a group of HR professionals in AAM. We regularly polled on this. Also, in November, the national Total Compensation Not for Profit Survey opens. If you participate, you get the survey for free. It's a great resource!
I hope this helps!
Roz Schaffer, SHRM-SCP, SPHR