Social Security taxes have been raised some 40 times since the program began. The initial Social Security tax was 2 percent (split between the employer and employee), capped at $3,000 of earnings. That made for a maximum tax of $60. Today, the tax is 12.4 percent, capped at $106,800, for a maximum tax of $13,234. Even adjusting for inflation, that represents more than an 800 percent increase.