Which HF bands have segments exclusively allocated to Amateur Extra licensees?

The FCC reserves the lower-frequency segments of certain highly congested HF bands exclusively for Amateur Extra class licensees. This provides an incentive for hams to upgrade their licenses to the highest tier. These exclusive Extra-class segments are located on the 80-meter, 40-meter, 20-meter, and 15-meter bands. The very bottom of the CW and phone sub-bands on these specific frequencies are off-limits to General and Advanced class operators. The newer WARC bands (30, 17, and 12 meters) as well as the 160-meter and 10-meter bands do not have sub-bands restricted solely to Extra class operators, meaning General class operators share the exact same frequency limits as Extra class operators on those bands.