Marijuana Tax Equity Act of 2013 - Amends the Internal Revenue Code to impose an excise tax on: (1) the sale of marijuana by producers or importers of such drug equal to 50% of the sales price, and (2) each person who is engaged in a marijuana enterprise. Defines "marijuana enterprise" to mean a producer, importer, manufacturer, distributor, retailer or any person who transports, stores, displays, or otherwise participates in any business activity that handles marijuana or marijuana products.

Requires any person who engages in a marijuana enterprise to obtain a permit to engage in such business. Imposes civil and criminal penalties for violations of the requirements of this Act.