Roth IRA contributions must be based on earnings as an employee or from self-employment. Executor fees, while included in gross income, are not treated as self-employment income for someone who is not in the trade or business of being an executor (i.e., someone who serves as one for a relative).
Eligible taxpayers may claim a tax credit for 10%, 20%, or 50% of up to $2,000 of retirement plan contributions.