The all-dry fabrication of porous poly(methacrylic acid)-based membranes displaying tunable dissolution behaviors in aqueous media is presented. Poly(methacrylic acid) (PMAA) membranes were fabricated using a low temperature, solventless technique with gaseous initiator and monomer precursors. The PMAA was then converted to poly(methacrylic acid-co-methacrylic anhydride) by thermal annealing. By controlling the annealing time, the methacrylic anhydride (MAN) content was varied, which allowed for the dissolution behavior to be tuned. The incorporation of MAN moieties in the membranes also allowed for crosslinking via a vapor phase reaction with 1,3-diaminopropane. The membranes can be deposited on a variety of substrates, including gauze.