Description of Business	3 Months Ended
Mar. 31, 2019
Description Of Business
Description of Business	1. Description of Business Mewbourne Energy Partners 09-A, L.P., (the “Registrant” or the “Partnership”), a Delaware limited partnership engaged primarily in oil and gas development and production in Texas, Oklahoma, and New Mexico, was organized on February 26, 2009. The offering of limited and general partner interests began May 1, 2009 as a part of a private placement pursuant to Section 4(2) of the Securities Act of 1933 and Regulation D promulgated thereunder, and concluded August 28, 2009, with total investor contributions of $66,210,000 originally being sold to accredited investors of which $62,140,000 were sold to accredited investors as general partner interests and $4,070,000 were sold to accredited investors as limited partner interests. During 2011, all general partner equity interests were converted to limited partner equity interests. In accordance with the laws of the State of Delaware, Mewbourne Development Corporation (“MD”), a Delaware Corporation, has been appointed as the Partnership’s managing general partner. MD has no significant equity interest in the Partnership.

The entire disclosure for the business description and basis of presentation concepts. Business description describes the nature and type of organization including but not limited to organizational structure as may be applicable to holding companies, parent and subsidiary relationships, business divisions, business units, business segments, affiliates and information about significant ownership of the reporting entity. Basis of presentation describes the underlying basis used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-URI http://asc.fasb.org/topic&trid=2122369

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-URI http://asc.fasb.org/topic&trid=2122149

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-URI http://asc.fasb.org/topic&trid=2134479

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