Auto increment column in SQL server with select

Question

Hello I am populating a table with data from a different table. These are both pre-existing tables that have data in them. My script is almost working. It selects the appropriate values from the selection table and inserts the new record into the target table, but it is the ID column value that is problematic. I need the ID value to auto-increment based on the previous row. Instead of auto incrementing based on the previous row which is at a value of 268564, the script places a 1 and auto-increment from there as in 1, 2, 3 etc. I need the new row's ID to be 268565. Please see below, thanks all.

set identity_insert Table A ON;
INSERT INTO Table A 
(ID, Field2, Field3, Field4, Field5)

SELECT ROW_NUMBER() OVER (ORDER BY Table A.[ID]) AS Number, Field2, Field3, 0, Field4, Field5

FROM Table B
LEFT JOIN Table A
ON Table A.[match] = Table B.[match]
WHERE 
Table B.[match] = 44593
set identity_insert Table A OFF

ID	Field1	Field2	Field3	Field4
268564	table A value1	table A value2	table A value3	table A value4
1	table B value1	table B value2	table B value3	table B value4

Answer 1

Hello all thanks for your help. I was able to figure it out. I needed to use

 ROW_NUMBER() OVER (order by (select 1))+ (SELECT COALESCE(MAX(Table A.[ID]),0) FROM Table A)