That was reasonably helpful! Thank you - the error has gone away, however, now I have a different issue. I did the following:
- switched the variables to Variant instead of Long
- Referenced them as suggested using.Value

Now I have a section of code that is trying to use those values in a summation and on the sheet, there is a #Name? because it is adding a value and 'Alt1Lab'.
ActiveCell.Offset(2, 0).Select
    ActiveCell.Formula = "='Bid Summary'!D17+Alt1Lab+Alt2Lab+Alt3Lab+Alt4Lab+Alt5Lab"
    ActiveCell.Offset(0, 1).Select
    ActiveCell.Formula = "='Bid Summary'!E17+'Bid Summary'!I32+Alt1Mat+Alt2Mat+Alt3Mat+Alt4Mat+Alt5Mat"
    ActiveCell.Offset(0, 1).Select
    ActiveCell.Formula = "='Bid Summary'!F17+Alt1Sub+Alt2Sub+Alt3Sub+Alt4Sub+Alt5Sub"
    ActiveCell.Offset(0, 1).Select
    ActiveCell.Formula = "='Bid Summary'!H17+Alt1Rent+Alt2Rent+Alt3Rent+Alt4Rent+Alt5Rent"
    ActiveCell.Offset(0, 1).Select
    ActiveCell.Formula = "='Bid Summary'!G17+Alt1Own+Alt2Own+Alt3Own+Alt4Own+Alt5Own"
After the macro runs, the cell states ='Bid Summary'!D17+Alt1Lab+Alt2Lab+Alt3Lab+Alt4Lab+Alt5Lab and the #NAME? code appears.

Any other suggestions?