Low-mass K and M dwarf stars are becoming increasingly targeted in exoplanet transit and radial velocity surveys. Their low mass, small radii, and low luminosity conspire to make Earth-sized planets in the stellar habitable zone relatively easier to detect than their counterparts around sun-like stars. Notably, properties of detected planets and planet candidates are defined relative to the host star, making knowledge about host star properties critical to our understanding of the exoplanet population. Stellar evolution models offer a fast and efficient means of fully characterizing properties of potential exoplanet host stars. However, there is strong evidence suggesting that stellar evolution models cannot accurately predict the properties of low-mass stars in the solar neighborhood. In this talk, I will discuss current problems posed by the low-mass star population, results from ongoing studies to uncover the physical origin for observed disagreements, and solutions investigated to redeem stellar evolution theory.