  In this talk, we summarize how QCD evolution can be exploited to improve the
treatment of transverse momentum dependent (TMD) parton distribution and
fragmentation functions. The methods allow existing non-perturbative fits to be
turned into fully evolved TMDs that are consistent with a complete
TMD-factorization formalism over the full range of kT. We argue that evolution
is essential to the predictive power of calculations that utilize TMD parton
distribution and fragmentation functions, especially TMD observables that are
sensitive to transverse spin.
