as an intern, you do 5 floor months (with nightfloat 7 nights/week) and 2-2.5 NICU/nursery months with q4 call. the rest consists of 1-2 months of ER; 2+ outpatient months, which typically have either a couple of weekend ER shifts per block or q4 overnight cross cover; your guaranteed call-free block, which is either elective or "primary care block;" and of course vacation (almost 5 weeks in intern year, more than other programs i've seen!). sometimes you get lucky and have no cross cover at all on some outpatient blocks. i had 2 months of call-free rotations (elective, child development, and allergy clinic) my intern year.
junior year also has less call time than it appears at first. this includes:
1) 2 weeks of call free elective
2) 2-4 weeks of sick call during which you basically hang out anywhere within an hour of the hospital in case you get called in (on my sick call, i spent several afternoons at the beach and only got called in twice to cover two ER shifts)
3) 4 weeks of elective with q4 cross-cover call (other than those cross-cover calls, expectations are low for our electives - residents often spend elective time with their kids, doing fellowship/job interviews, or just relaxing)
4) several junior rotations are call-free as well, including the ICP (step-down ICU), bone marrow transplant (call free but you have to round on saturday morning), and outpatient GI (morning clinics only for 10 days!). They're planning on making outpatient pulmonary call-free next year.
5) one of the nicest things about junior year is that unlike intern year, when you stay post-call 'til 12 or 1 on weekdays, junior year you typically sign out and leave immediately after rounds. if you've had a good night and you get done at 9 am, you have a whole day off!
senior year, with its months of elective and 3 months of "career development block," is a cushy experience!!