I am considering converting my 403b to a Roth IRA. Can I do this directly or must I first covert it to a regular IRA then to a Roth.

Only a traditional IRA may be converted to a Roth IRA. Therefore, you must first put your 403(B) distribution into a traditional IRA (which is not a taxable event), then convert the IRA to a Roth (which IS a taxable event).

Moreover, before you can put your 403(B) into an IRA, you have to be eligible for a distribution from the 403(B). Generally, this requires that you have a "qualifying event," such as attaiment of age 59-1/2 or separation from service. Death and disability are also qualifying events, but highly inconvenient.

Hope this helps. Good luck!

can't you use the 90-24 transfer and transfer the money into an IRA?

No. Revenue Ruling 90-24 is used only when moving funds from one 403(B) account to another 403(B) account. A direct rollover is used to roll money from a 403(B) into an IRA, assuming that a distribution from the 403(B) is permissible under the law.