Joining Tables Through Multiple Criteria

I have two tables a and b, where I want to add columns from b to a with a criteria. The columns will be added by month criteria. There is a column in b table called stat_month which ranges from 1 (Jan) to 12 (Dec). I want to keep all the records in a, and join columns from b for each month. I do not want to loose any row from a if there is no data for that row in b.

Here is table a:

CREATE TABLE #A(
naics INT,
ust_code INT,
port INT,
all_qty_1_yr FLOAT,

[Code] ....

And here is table b:

CREATE TABLE #B(
naics INT,
ust_code INT,
port INT,
stat_month INT,
Cum_qty_1_mo FLOAT,

[Code] ....

I do not know how to have the multiple joins for 12 different months and what join I have to use. I used left join but still I am loosing not all but few rows in a, I would also like to know how in one script I can columns separately from stat_mont =’01’ to stat_month =’12’

/****** Script for SelectTopNRows command from SSMS ******/
SELECT a.[naics]
,a.[ust_code]
,a.[port]
,a.[all_qty_1_yr]
,a.[all_qty_2_yr]

[Code] ....

output should have all columns from a and join columns from b when the months = '01' (for Jan) , '02' (for FEB), ...'12' (for Dec): Output table should be something like

* columns from a AND JAN_Cum_qty_1_mo JAN_Cum_qty_2_mo JAN_Cum_all_val_mo JAN_Cum_air_val_mo JAN_Cum_air_wgt_mo JAN_Cum_ves_val_mo FEB_Cum_qty_1_mo FEB_Cum_qty_2_mo FEB_Cum_all_val_mo FEB_Cum_air_val_mo FEB_Cum_air_wgt_mo FEB_Cum_ves_val_mo .....DEC_Cum_qty_1_mo DEC_Cum_qty_2_mo DEC_Cum_all_val_mo DEC_Cum_air_val_mo DEC_Cum_air_wgt_mo DEC_Cum_ves_val_mo (FROM TABLE b)