21st federal electoral district of the State of Mexico

Under the 2023 districting plan adopted by the National Electoral Institute (INE), which is to be used for the 2024, 2027 and 2030 federal elections, the 21st district is located in the state's eastern panhandle and covers 174 electoral precincts () across 12 of its 125 municipalities: • Amecameca, Atlautla, Ayapango, Cocotitlán, Ecatzingo, Juchitepec, Ozumba, Temamatla, Tenango del Aire, Tepetlixpa, Tlalmanalco and the eastern portion of Ixtapaluca. The head town (), where results from individual polling stations are gathered together and tallied, is the city of Amecameca de Juárez. In the 2020 Census, the district reported a total population of 410,835. ==Previous districting schemes==

Under the previous districting plans enacted by the INE and its predecessors, the 21st district was situated as follows: 2017–2022 :Ten municipalities in the eastern panhandle: Amecameca, Atlautla, Ayapango, Ecatzingo, Juchitepec, Ozumba, Tenango del Aire, Tepetlixpa, Tlamanalco and the eastern portion of Ixtapaluca. The head town was at Amecameca de Juárez. 2005–2017 :A portion of the municipality of Naucalpan de Juárez. 1978–1996 :The municipalities of Acolman, Apaxco, Axapusco, Hueypoxtla, Jaltenco, Melchor Ocampo, Nextlalpan, Nopaltepec, San Martín de las Pirámides, Tecámac, Temascalapa, Teoloyucan, Teotihuacán, Tequixquiac, Tezoyuca, Tultepec and Zumpango, with its head town at Zumpango de Ocampo. ==Deputies returned to Congress ==