The evolutionary phases in going from a Type Ia supernova explosion to a 1000-yr-old remnant are reviewed. The explosion sets up the density and composition structure of the ejecta and can have radiative effects on the surroundings. The early shock interactions may be observable at radio and X-ray wavelengths if the circumstellar density is sufficiently high. The later interaction with the interstellar medium is affected by the collisionless shock physics and hydrodynamic instabilities.