Some people disagree with me, but Form 6198 is not used to limit a loss due to Basis.  It should give the same result and is a 'cheat' work-around, but the way I understand things Form 6198 should not be used.  You would only enter the amount of loss that is allowed (such as Box 1), then manually enter the unallowed amount in future years once Basis is restored.

If you want to file Form 6198, you can either (a) manually fill it out, manually limit the Basis, and attach the form to the tax return, or (2) use ProSeries Professional on a Pay-Per-Return basis.