According to the League of American Theatres and Producers, if tickets were purchased through a credit card (for shows not at Nederlander theatres), in most cases the card will automatically be credited with a refund.
Those who purchased tickets at a theatre's box office with cash or by check should return to the box office for a refund. If the theatre's box office is closed, a refund may be obtained by mail. For refunds to August: Osage County, Avenue Q, A Bronx Tale, Chicago, A Chorus Line, The Color Purple, Curtains, Dr. Seuss' How the Grinch Stole Christmas, Duran Duran, The Farnsworth Invention, Is He Dead?, Jersey Boys, Les Misérables, Mamma Mia!, Monty Python's Spamalot, The Phantom of the Opera, Rock 'n' Roll, The Seafarer and Spring Awakening, mail the ticket to Telecharge.com, 411 Hackensack Avenue, Hackensack, NJ, 07601.
Those who purchased tickets on-line through Theatre Development Fund (tdf.org) will also be refunded: the ticket price will be credited to your credit card. Those who purchased tickets by mail through TDF will receive a refund check from TDF. If tickets were purchased elsewhere, the League advises ticket holders to return to or contact the point of purchase. It is also advisable to retain a photocopy of the tickets.