A method for forming a biodegradable polylactic acid suitable for use in fibers is provided. In one embodiment, for example, a polylactic acid is melt blended with an alcohol to initiate an alcoholysis reaction that results in a polylactic acid having one or more hydroxyalkyl or alkyl terminal groups. By selectively controlling the alcoholysis conditions (e.g., alcohol and polymer concentrations, catalysts, temperature, etc.), a modified polylactic acid may be achieved that has a molecular weight lower than the starting polylactic acid. Such lower molecular weight polymers also have the combination of a higher melt flow index and lower apparent viscosity, which is useful in a wide variety of fiber forming applications, such as in the meltblowing of nonwoven webs.