Roth IRA Limit if you are married filing separately

[TaxLearner]

I read that the Income requirement for Roth IRA if you are married filing separately is $10,000 but if you are married filing jointly, it is between $198,000 to $208,000. Can you please explain why the roth ira income limit for married filing separately is so low? Please let me know if I misunderstood the rule.

[Mike9241]

ask Congress, it's their law. but one would assume to prevent it in cases where one spouse had say 210,000 in AGI and the other's AGI was 10,000 or under. 

could it have made a provision in the tax laws for this situation - yes. but spouses who MFS don't have to disclose their info to the other spouse

there is an exception to this limitation

if you MFS and lived apart at all times during the year you are treated as single.