[1] It elects one deputy to the lower house of Congress for each three-year legislative session by means of the first-past-the-post system.

Votes cast in the district also count towards the calculation of proportional representation ("plurinominal") deputies elected from the fifth region.

The 7th district's head town was at Zacapu and it covered 12 municipalities in that region of the state: Coeneo, Charapan, Cherán, Chilchota, Erongarícuaro, Los Reyes, Nahuatzen, Paracho, Purépero, Quiroga, Tangancícuaro and Zacapu.

[9][8] The districting scheme in force from 1978 to 1996 was the result of the 1977 electoral reforms, which increased the number of single-member seats in the Chamber of Deputies from 196 to 300.

[10] The 7th district's head town was at Tacámbaro in the central region of the state and it was composed of 11 municipalities: Ario, Carácuaro, Churumuco, Huetamo, Madero, Nocupétaro, San Lucas, Tacámbaro, Tiquicheo, Tumbiscatío and Turicato.