Exhibit 5.1

[Letterhead of Baker, Donelson, Bearman, Caldwell & Berkowitz, PC]

December 9, 2015

Board of Directors

Mid-America Apartment Communities, Inc.

6584 Poplar Avenue, Suite 300

Memphis, TN 38138

Gentlemen:

We have acted as counsel to Mid-America Apartment Communities, Inc., a Tennessee corporation (the “Company”), and Mid America Apartments, L.P., a Tennessee limited partnership, in connection with the offering of up to 4,000,000 shares (the “Shares”) of the Company’s common stock, par value $0.01 per share (the “Common Stock”), all of which Shares are to be offered and sold by the Company from time to time in accordance with the terms of separate Distribution Agreements (collectively, the “Distribution Agreements”), and as described in the prospectus supplement dated December 9, 2015 (the “Prospectus Supplement”) and the accompanying prospectus dated December 9, 2015 (such documents, collectively, the “Prospectus”) that form part of the Company’s effective registration statement on Form S-3, as amended (File Nos. 333-208398 and 333-208398-01) (the “Registration Statement”), which was filed with the Securities and Exchange Commission (the “Commission”) on December 9, 2015 pursuant to the Securities Act of 1933, as amended (the “Act”). This opinion letter is furnished to you at your request to enable you to fulfill the requirements of Item 601(b)(5) of Regulation S-K, 17 C.F.R. § 229.601(b)(5), in connection with the Registration Statement.

For purposes of this opinion letter, we have examined such documents as we have deemed necessary, including copies of the following documents:

In our examination of the aforesaid documents, we have assumed the genuineness of all signatures, the legal capacity of natural persons, the accuracy and completeness of all documents submitted to us, the authenticity of all original documents, and the conformity to authentic original documents of all documents submitted to us as certified, telecopied, photostatic, or reproduced copies. We have also assumed the accuracy, completeness and authenticity of the foregoing certifications of officers and statements of fact, on which we are relying, and have made no independent investigations thereof. This opinion letter is given, and all statements herein are made, in the context of the foregoing.

Based upon the foregoing, and having regard for such legal considerations as we have deemed relevant, we are of the opinion that:

Our opinion is subject to the following qualifications and limitations:

This opinion letter has been prepared solely for your use and should not be quoted in whole or in part or otherwise be referred to, nor filed with or furnished to any governmental agency or other person or entity, without the prior written consent of this firm. We consent to the filing of this opinion as Exhibit 5.01 to the Registration Statement and to the reference to this firm under the heading “Legal Matters” therein. In giving this consent, we do not admit that we are in the category of persons whose consent is required by Section 7 of the Act.