No The can must have at least 1/2 inch clearance from any lumber. IC is INSULATION CONTACT.
Edward.
410-66(a) NEC.1996 Recessed portion of lighting fixture enclosures, other than at the point of support shall be spaced at least 1/2 inch from combustible material. Exception: Recessed fixtured identified as suitable for insulation to be in direct contact with the fixture.
IC rated recessed housings do NOT require any clearance from combustible material. The paper backing on older insulation is one of the most combustible items you will find in attics.
Mark, You must be thinking of 4” low voltage housings. Halo, Juno, Lightolier, Nora, DMF, Elco, Etc make 4” line voltage IC housings that are not much larger than the equivalent TC versions.