The Smithsonian offers an annual promotion which is their Museum Day Live! offer. This exciting deal allows you to get 2 free tickets to hundreds of museums across the entire country. There are often good deals that allow you to save a good amount of money on admission for your family.
Taken from the Museum Day Live! website, instructions from their FAQs are:
When is Museum Day Live!?
Saturday, September 24, 2016
How do I find out if a museum in my area is participating?
Visit Find a Museum to locate participating museums near you. Zoom in on the map or search by state, zip code or museum name.
How do I get free admission?
To Get a Ticket, enter your email address, name, state and museum of choice. You will receive an email from firstname.lastname@example.org with a link to your ticket immediately.
Does everyone get free admission?
To get free admission, guests must present an official Museum Day Live! ticket. This ticket provides general admission for ticketholder plus one guest (not valid for special exhibits, parking, IMAX film screening or any other offer).
Can I bring my whole family to Museum Day Live!?
Each ticket provides general admission for ticketholder plus one guest. If you go to Museum Day Live! with more than one guest, your other guests will have to pay full admission.
Can I download a ticket for more than one museum?
No, you may only download one ticket for one museum.
Are all museums in the country participating in Museum Day Live!?
Museums must elect to participate. Find a museum in your area now.