Mammilaria wrightii var. wilcoxii has been documented in New Mexico from Hidalgo, Doña Ana, Grant, and Luna counties (SEINet 2019).  It also occurs in Arizona in Cochise, Santa Cruz, and Graham counties, and is known from the Mexican state of Sonora (and possibly Chihuahua).  NatureServe ranks Mammilaria wrightii var. wilcoxii globally secure and secure in AZ (G4/T4, S4).  Although the New Mexico rank is S2 (imperiled), this rank is outdated and does not reflect current knowledge (last updated in 1988).  Mammilaria wrightii var. wilcoxii is not considered a United States Department of the Interior, Bureau of Land Management (BLM) or United States Department of Agriculture, Forest Service (Forest Service) Sensitive Species in Arizona or New Mexico.  The New Mexico Rare Plant Technical Council removed the species from consideration as a rare plant because it was considered too common and widespread (NMRPTC 1999).  It was removed from the state list of endangered plant species in 2020.