IRS says:
You are taxed when you start receiving payments under that annuity contract.
Tax treatment. If only deductible contributions were
made to your traditional IRA since it was opened (this includes all your traditional IRAs, if you have more than
one), the annuity payments are fully taxable.
If any of your traditional IRAs include both deductible and nondeductible contributions, the annuity payments
are taxed as explained earlier under Distributions Fully or Partly Taxable.
