Why do you want a code

for e.g a2 is 1234 and b2 is example text1

then in c2 type this formula

=IF(OR(ISBLANK(A2),ISBLANK(B2)),"",A2&B2)

copy c2 down the 5000 rows. to quickly copy take the cursor to the bottom
right the cursor will turn to + then click this it will be copied down.
now check

Thanks for the info, but I may not have been clear about what I was trying to do...

I'm importing legacy data from an out of date defect tracking system into a new system (JIRA). All of the fields from the defects have a column in the CSV file (defect id is column A, and steps to reproduce is column B, etc...). When the reports were generated from the old system the steps to reproduce were imported into successive rows for each step while the rest of the data for each defect is in just one row. So there can be multiple rows in column B (and it varies for each defect) for each defect ID in column A.

For example:

Cell A2 contains defect ID 1234.
Cells B2:B5 each contain one sentence.
Cell A6 contains defect ID 1235.
Cells B6:B8 each contain one sentence.

I need a macro which will start in cell A2, determine that it is not null and then combine the text in each successive row in column B until a cell in column A is populated again. So in the above example cells B2:B5 would be combined into cell B2 and cells B6:B8 would be combined into cell B6.

Basically I know that the macro above will combine the data correctly, I just need to figure out how to define the range based on if column A remains null.

Sorry, it's hard to explain... Thanks again for any and all help you can provide!

Your data is from A1 to B7 with row1 having column headings.
the macro will work if your have more rows provided the sheet starts from A1

try this macro

Sub test()
Dim rng As Range, x() As String, c As Range
Dim j As Integer, k As Integer, lastrow As Integer, y As String
 Worksheets("sheet1").Activate
 Columns("c:c").Columns.Delete
lastrow = Range("B1").End(xlDown).Row
Set rng = Range("a2")
'msgbox rng.Address
line2:
'msgbox rng.End(xlDown).Row
If rng.End(xlDown).Row > lastrow Then
j = rng.Offset(0, 1).End(xlDown).Row - rng.Row + 1
Else
j = rng.End(xlDown).Row - rng.Row
End If
'msgbox j
ReDim x(1 To j)
y = ""
For k = 1 To j
x(k) = rng.Offset(k - 1, 1)
y = y & " " & x(k)
'msgbox x(k)
'msgbox y
Next
rng.Offset(0, 2) = y
Set rng = rng.End(xlDown)
'msgbox rng.Address
If rng.Offset(0, 1) = "" Then
GoTo line1
Else
GoTo line2
End If
line1:
Columns("a:c").AutoFit
End Sub

Thanks Venkat1926! It works, might require some slight tweaking but this saved me a lot of time and helps a ton!