I have a SIMPLE IRA from a previous employer. How long do I have to wait to roll it over into an IRA?

There are very specific rules regarding distributions of SIMPLE IRA funds. 

According to IRS guidelines, the rules revolve around payments or distributions received from a SIMPLE IRA during the 2-year period beginning on the date on which the individual first participated in any SIMPLE IRA plan maintained by the individual's employer (the "2-year period"). The 2-year period begins on the first day on which contributions made by the individual's employer are deposited in the individual's SIMPLE IRA. 

A distribution from a SIMPLE IRA during this 2-year period qualifies as a rollover contribution (and thus is not includable in gross income and is considered a tax-free trustee to trustee transfer) only if the distribution is paid into another SIMPLE IRA.  

If, during this 2-year period, an amount is paid from a SIMPLE IRA directly to the trustee of an IRA that is not a SIMPLE IRA, the payment is neither a tax-free trustee-to-trustee transfer nor a rollover contribution.  Rather, the payment is considered a distribution from the SIMPLE IRA and a contribution to the other IRA that does not qualify as a rollover contribution.

After the expiration of the 2-year period, an amount in a SIMPLE IRA may be transferred in a tax-free trustee-to-trustee transfer to an IRA that is not a SIMPLE IRA.