Building year to date aggregations using SQL

I need some help with building a monthly aggregation using only SQL.

Imagine the following table:

TranID  DateCode    Account Value
   1    20140101        1   5
   2    20140106        1   -3
   3    20140207        1   6
   4    20140409        1   3
   5    20140103        2   3
   6    20140215        2   7
   7    20140519        2   6

There are two accounts that have transactions on various dates. I would like to write code that gives me this result assuming we are in July:

MonthID     Account YTD
20140101        1   2
20140201        1   8
20140301        1   8
20140401        1   11
20140501        1   11
20140601        1   11
20140701        1   11
20140101        2   3
20140201        2   10
20140301        2   10
20140401        2   10
20140501        2   16
20140601        2   16
20140701        2   16

I'm thinking I should be able convert the dates to MonthCode using

DATEADD(day, -DAY(DateCode) + 1, DateCode) AS MonthCode

I'm thinking I should be able to solve this somehow by joining the table to itself but I don't really get the numbers right. Also I need to somehow get the months without transactions in as well..

Any and all help will be greatly appreciated!

Code to generate the mock data:

Create table #Tran(
TranID int identity(1,1),
DateCode Date,
AccountCode varchar(50),
Value int
);

insert into #Tran (DateCode, AccountCode, Value)
values ('20140101', '1', 5),
('20140106', '1', -3),
('20140201', '1', 6),
('20140401', '1', 3),
('20140101', '2', 3),
('20140201', '2', 7),
('20140501', '2', 6);