INVESTMENTS IN OPERATING PARTNERSHIPS (Details 3) - USD ($)		6 Months Ended
		Sep. 30, 2016	Sep. 30, 2015
Revenues
Rental		$ 5,211,464	$ 6,316,814
Interest and other		101,215	131,891
Operating Partnerships Revenues		5,312,679	6,448,705
Expenses
Interest		633,554	784,026
Depreciation and amortization		1,291,363	1,657,094
Operating expenses		4,190,981	4,750,149
Operating Partnerships Total Expenses		6,115,898	7,191,269
NET LOSS		(803,219)	(742,564)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[1]	(795,185)	(735,137)
Net loss allocated to other Partners		(8,034)	(7,427)
Series Fifteen [Member]
Revenues
Rental		1,174,081	1,349,023
Interest and other		26,849	30,803
Operating Partnerships Revenues		1,200,930	1,379,826
Expenses
Interest		154,795	182,807
Depreciation and amortization		279,803	339,402
Operating expenses		885,807	1,038,780
Operating Partnerships Total Expenses		1,320,405	1,560,989
NET LOSS		(119,475)	(181,163)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[2]	(118,280)	(179,351)
Net loss allocated to other Partners		(1,195)	(1,812)
Series Sixteen [Member]
Revenues
Rental		1,639,035	2,336,187
Interest and other		24,810	39,794
Operating Partnerships Revenues		1,663,845	2,375,981
Expenses
Interest		197,987	295,892
Depreciation and amortization		366,909	598,462
Operating expenses		1,318,902	1,631,545
Operating Partnerships Total Expenses		1,883,798	2,525,899
NET LOSS		(219,953)	(149,918)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[3]	(217,753)	(148,419)
Net loss allocated to other Partners		(2,200)	(1,499)
Series Seventeen [Member]
Revenues
Rental		1,026,457	1,221,132
Interest and other		17,039	21,168
Operating Partnerships Revenues		1,043,496	1,242,300
Expenses
Interest		106,241	145,301
Depreciation and amortization		314,896	362,917
Operating expenses		800,813	915,707
Operating Partnerships Total Expenses		1,221,950	1,423,925
NET LOSS		(178,454)	(181,625)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[4]	(176,668)	(179,808)
Net loss allocated to other Partners		(1,786)	(1,817)
Series Eighteen [Member]
Revenues
Rental		999,311	1,040,147
Interest and other		21,479	30,360
Operating Partnerships Revenues		1,020,790	1,070,507
Expenses
Interest		128,750	110,648
Depreciation and amortization		247,517	284,019
Operating expenses		861,838	840,923
Operating Partnerships Total Expenses		1,238,105	1,235,590
NET LOSS		(217,315)	(165,083)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[5]	(215,142)	(163,432)
Net loss allocated to other Partners		(2,173)	(1,651)
Series Nineteen [Member]
Revenues
Rental		372,580	370,325
Interest and other		11,038	9,766
Operating Partnerships Revenues		383,618	380,091
Expenses
Interest		45,781	49,378
Depreciation and amortization		82,238	72,294
Operating expenses		323,621	323,194
Operating Partnerships Total Expenses		451,640	444,866
NET LOSS		(68,022)	(64,775)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[6]	(67,342)	(64,127)
Net loss allocated to other Partners		$ (680)	$ (648)

[1] Amounts include $795,185 and $735,137 for 2016 and 2015, respectively, of loss not recognized under the equity method of accounting.

[2] Amounts include $118,280 and $179,351 for 2016 and 2015, respectively, of loss not recognized under the equity method of accounting.

[3] Amounts include $217,753 and $148,419 for 2016 and 2015, respectively, of loss not recognized under the equity method of accounting.

[4] Amounts include $176,668 and $179,808 for 2016 and 2015, respectively, of loss not recognized under the equity method of accounting.

[5] Amounts include $215,142 and $163,432 for 2016 and 2015, respectively, of loss not recognized under the equity method of accounting.

[6] Amounts include $67,342 and $64,127 for 2016 and 2015, respectively, of loss not recognized under the equity method of accounting.