If you you got your IDNYC in 2015 and you want a free year-long membership at the Museum of the Moving Image, you need to sign up ASAP.. View Full Caption Peter Aaron/Esto. Courtesy of Museum of Moving Image.

The city announced last week that it's extending free enrollment for its municipal ID program to the end of 2016, along with the option to get complimentary one-year memberships to 40 cultural institutions, including The Bronx Zoo and Metropolitan Museum of Art.

The mayor's office made it clear that the extension means that New Yorkers don't have to apply for their free-of-charge IDNYC at one of 29 centers by the end of 2015.

But it left many cardholders who had claimed their IDs in 2015 confused as to whether they would still have to activate their one-year memberships at each institution before New Year's Day, or if they now had all of 2016 to do so.

As it turns out, there is no easy answer.

"Each participating institution will determine how and until when to honor 2015 cardholders, so cardholders should contact individual institutions for their policy," a spokesperson at the mayor's office said in an email.

DNAinfo did the legwork so you don't have to.

Below you'll find the new membership policies for some of the most popular museums, zoos and performance spaces collaborating with the city, including those that have an agreement with the city to start signing up cardholders for memberships in 2016. (Note: not all participating institutions have finalized their membership policies for 2015 cardholders yet.)

You'll have to get here before the end of 2015 to register for your year-long membership:

► Museum of the Moving Image

Location: 36-01 35th Ave., Astoria

Hours: 10:30 a.m. to 5:00 p.m. Wednesdays–Thursdays; 10:30 a.m. to 8:00 p.m. Fridays; 11:30 a.m. to 7:00 p.m. Saturdays and Sundays; closed Mondays and Tuesdays

You have until the end of January to activate your 2015 membership here:

► Bronx Zoo (as long as you haven't been a member since Jan. 1, 2012)

Location: 2300 Southern Blvd., Bronx

Hours: 10 a.m. to 4:30 p.m. daily

► Brooklyn Botanic Garden

Location: 150 Eastern Pkwy., Fort Greene

Hours: 8 a.m. to 4:30 p.m Tuesday–Friday; 10 a.m. to 4:30 p.m. Tuesday–Friday; closed Mondays

► Guggenheim Museum

Location: 1071 Fifth Avenue, Upper East Side

Hours: 10 a.m. to 5:45 p.m Sunday-Wednesday and Friday; 10 a.m. to 7:45 p.m. Saturday; closed Thursdays

► Metropolitan Museum of Art

Location: 1000 Fifth Avenue, Upper East Side

Hours: 10 a.m.–5:30 p.m. Sunday–Thursday;10:00 a.m.–9:00 p.m. Friday-Saturday

► New York Botanical Garden

Location: 2900 Southern Blvd., the Bronx

Hours: 10 a.m.-6 p.m. Tuesday–Sunday; closed Mondays

► New York City Ballet

Location: 20 Lincoln Center Plaza, Upper West Side

Hours (box office): 10 a.m. to 7:30 p.m. Monday; 10 a.m. to 8:30 p.m. Tuesday-Saturday; 11:30 a.m. to 7:30 p.m. Sunday

Sign up here before the end of February:

► Queens Botanical Garden

Location: 43-50 Main Street, Flushing

Hours: 8 a.m. to 4:30 p.m. Tuesday through Sunday; closed Mondays

You have all of 2016 to sign up for memberships at these institutions, so breathe easy:

► American Museum of Natural History

Location: Central Park West at 79th Street, Upper West Side

Hours: 10 a.m. to 5:45 p.m. daily

► Brooklyn Academy of Music

Location: 30 Lafayette Ave.; 651 Fulton St; and 321 Ashland Pl, Fort Greene

Hours: Vary depending on the building

► Brooklyn Museum

Location: 200 Eastern Pkwy.

Hours: 11 a.m. to 6 p.m. Wednesday, Friday, Saturday, Sunday; 11 a.m. to 10 p.m. Thursday; closed Monday, Tuesday

► Carnegie Hall

Location: 881 7th Ave., Midtown

Hours (box office): 11 a.m. to 6 p.m., Monday–Saturday; 12 p.m. to 6 p.m. Sunday

► Museum of Modern Art (added to the list of participating institutions this month, you can't sign up here until Jan. 1 2016)

Location: 11 W. 53rd St., Midtown

Hours: 10:30 a.m. to 5:30 p.m. every day except Friday; 10:30 a.m. to 8 p.m. Friday

► The Metropolitan Opera (added this month; wait until Jan. 1 to sign up here)

Location: 30 Lincoln Center Plaza, Upper West Side

Hours: Monday – Saturday: 10 a.m. to 8 p.m., Sunday: Noon to 6 p.m.

► Staten Island Museum

Location: 1000 Richmond Terr., Building A, Snug Harbor; 75 Stuyvesant Place, St. George

Hours: 11 a.m. to 5 p.m. Monday-Friday; 10 a.m. to 5 p.m. Saturday; 12 p.m. to 5 p.m. Sunday

We'll update the list above as we learn more.

Editor’s Note: This story was updated Dec. 22 to state AMNH will allow 2015 cardholders to claim memberships through 2016. It was updated again Dec. 23 to state that the Guggenheim is not giving 2015 cardholders free one-year memberships. It was updated a third time Dec. 24 to include the New York Botanical Garden among institutions signing up 2015 cardholders for memberships until the end of January 2016. It was updated a fourth time Dec. 30, to reflect the Guggenheim's adjusted policy, add the Queens Botanical Garden's deadline, and clarify that cardholders cannot sign up at the MoMA or the Met Opera until Jan. 1, 2016.