Social Security 2100 Act This bill increases various Old Age, Survivors, and Disability Insurance (OASDI) benefits and related taxes. The bill increases the primary insurance amount (e.g., the amount a Social Security beneficiary receives if the beneficiary begins receiving benefits at normal retirement age) by increasing the percentage of the beneficiary's average indexed monthly earnings used to calculate the amount. The Bureau of Labor Statistics shall publish a Consumer Price Index for Elderly Consumers, which the Social Security Administration (SSA) shall use to calculate cost-of-living adjustments to benefits. Currently, the SSA uses a price index for wage earners to make such adjustments. The bill increases the minimum benefit amount for individuals who worked for more than 10 years by creating an alternative minimum benefit. A qualifying beneficiary shall receive that alternative minimum if it is higher than the standard calculated benefit amount. The bill increases the income threshold that a beneficiary must reach before Social Security benefits are taxable. Increased benefits from this bill shall not count as income when determining an individual's eligibility or benefit amounts for (1) Medicaid, (2) the Children's Health Insurance Program, or (3) the Supplemental Security Income program. Income above $400,000 shall be included when calculating Social Security benefits and taxes. The bill also increases rates for the payroll and self-employment taxes that fund OASDI. The bill establishes the Social Security Trust Fund, which replaces the Federal Old-Age and Survivors Insurance Trust Fund and the Federal Disability Insurance Trust Fund.