This information comes directly from AA -


Estimates of A.A. Groups and Members

Because A.A. has never attempted to keep formal membership lists, it is extremely difficult to obtain completely accurate figures on total membership at any given time. Some local groups are not listed with the U.S./Canada General Service Office. Others do not provide membership data, thus are not recorded on the G.S.O. computer records. The membership figures listed below are based on reports to the General Service Office as of January 1, 2007, plus an average allowance for groups that have not reported their membership.
There is no practical way of counting members who are not affiliated with a local group.

Estimated A.A. Membership and Group Information
Groups in U.S.	55,244
Members in U.S	1,248,394
Groups in Canada	4,849
Members in Canada	93,986
Groups Overseas	55,092
Members Overseas	702,510
Internationalists	36
Groups in Correctional Facilities (U.S./Canada)	1,585
Members in Correctional Facilities	39,964
Lone Members	235
Total Members:	2,085,125
Total Groups:	116,773

INTERNATIONALISTS (SEAGOING A.A.s)
Approximately 36 persons in naval service or the merchant marine on sea duty describe themselves as "A.A. Internationalists." General Service Office staff members correspond with these members and make it possible for them to correspond with each other. Internationalists have been responsible for starting and encouraging local A.A. groups in many ports.
LONERS
Some 235 men and women living in isolated areas throughout the world (or in areas where it has not been possible to form a local group) are listed at the General Service Office as Lone Members. Many achieved sobriety solely through study of A.A. literature. They correspond with G.S.O. and with their counterparts in other sections of the world. In a number of cases, notably U.S. military installations overseas, Loners have been responsible for establishing local groups.