The sequential bond energies of Cu(CO)(x)(+) and Ag(CO)(x)(+) (x = 1-4) are determined by collision-induced dissociation in a guided ion beam tandem mass spectrometer. Values (in eV) for the 0 K (COCu+-CO bond energies are found to be 1.54 +/- 0.07, 1.78 +/- 0.03, 0.78 +/- 0.04, and 0.55 +/- 0.03 for x = 1-4, respectively, while those for (COAg+-CO are determined to be 0.92 +/- 0.05, 1.13 +/- 0.04, 0.57 +/- 0.08, and 0.47(-0.04)(+0.19) for x = 1-4, respectively. The energies for loss of one CO from the mono- and dicarbonyls of both metal ions disagree with one set of theoretical values, but those for Ag(CO)(x)(+) (x = 1-3) are in excellent agreement with more recent theoretical predictions and help verify the trends in stability found for these complexes in recent synthetic studies. Trends in bond dissociation energies with increasing ligation are discussed for both systems and compared to those for isoelectronic Ni(CO)(x) and Co(CO)(x)(-) complexes.