If there is already paint on your stucco, you cannot stucco over it. This includes patches and repairs. If your stucco has fared well under the paint then you can paint again. become trapped in the wall between the membrane and the paint. This can cause the paint to bubble, peel, and chip as the moisture forces a way out.
If your stucco is in good shape, your best option is to clean it with a pressure washer and then cover it with a "fog coat". This is a very thin coat of Portland cement, water, and pigment (no sand) that covers the surfaces like paint, adding a layer of color that bonds to the structure of the existing stucco. If the stucco is cracked, chipped, or spalled, it needs to be repaired and then recovered with a whole new color coat.
If there is already paint on your stucco, you cannot stucco over it. This includes patches and repairs. If your stucco has fared well under the paint then you can paint again.
The following are photos of PAINTED stucco that is failing.
