subreport parameters not pulling data right

I have a main report pulling two Benefit Plan IDs (ID #1 and #2). I have a subreport that also pulls the same Benefit Plan IDs. I need it to display like this:

Main Report: Benefit Plan ID 1
SubReport: Benefit Plan ID 1

Main Report: Benefit Plan ID 2
SubReport: Benefit Plan ID 2

BUT, it is showing both Benefit Plan IDs in the subreport for each ID in the main report. It is displaying the results like this:

Main Report: Benefit Plan ID 1
SubReport: Benefit Plan ID 1
SubReport: Benefit Plan ID 2

Main Report: Benefit Plan ID 2
SubReport: Benefit Plan ID 1
SubReport: Benefit Plan ID 2

How do I fix this I have a report parameter created in the subreport called "BenefitPlanID" and it is linked to the "BenefitPlanID" column in the main report.

Thanks for any help!

jenr