While the AgentExpress platform uses the same quoting algorithms as healthcare.gov, there are a few instances where the quoted totals may come back different than what was quoted.
When eligibility is determined, CMS verifies against outside sources such as the IRS and Social Security Office to make the final determination. If the applicant has pre-existing tax troubles (owes back taxes, has not reconciled previous tax credits), they qualify for employer coverage (group, COBRA) or Medicaid, or their major income source is Social Security, this will negatively affect their subsidy, resulting in a higher responsibility amount. In many cases however, the discrepancy is due to differing information between the quote and application details.
Most often, your best resource is the eligibility letter obtained at the end of the application. However, if you have additional questions regarding your client's eligibility, you'll need to call the Agent/Broker Hotline at 855-788-6275.