No, because excommunication deprives one of the common spiritual prayers of the Church (St. Paul speaks of it as "delivering one up to Satan"), not just participation in the sacraments. Thus there is a real difference between the juridical punishments of interdict and excommunication.
The commission of any grave sin (such as joining the Freemasons) means that one should not receive holy Communion before having confessed and received absolution, but this doesn't constitute even a legal punishment: the sin, after all, is imposed by yourself and not ecclesiastical authority. And so it's not the same as excommunication. Though if you live in the diocese of Lincoln you will still be excommunicated if you join the Freemasons!
Hmm... what about this?
The adequate and general effect of excommunication is sufficiently evident thus far, from the explanation of the definition. In particular, the definitely classified canonical effects follow: exclusion from divine services of the Church, deprivation of the Sacraments (and sometimes sacramentals); exclusion from the public prayers of the Church, either by way of satisfaction or impetration; loss of the right to participate in legal acts of the Church; loss of income from ecclesiastical office; and loss of right to social intercourse in case of vitandus. Canon law distinguishes two fora or courts: the sacramental, or the tribunal of Penance, and the non-sacramental, either public or private. When the penitent appears in the sacramental forum, the Roman Ritual prescribes the same formula for absolution from excommunication as that used for remission of sin. In the non-sacramental forum, since absolution is a jurisdictional act, any formula expressing the effect intended may be employed. Following the general law of jurisdiction as it applies to censures, excommunication may be taken away by the one who had inflicted it, his superior, delegate, or successor.
Source: New Catholic Dictionary
Deprivation of the Sacraments, i.e., Communion seems like it would fit within the confines of Canon law mentioned above for
Theodon mentioned this link earlier and I found this interesting too:
The present legislation of the Church is contained in canon 1374:
Can. 1374 A person who joins an association which plots against the Church is to be punished with a just penalty; one who promotes or takes office in such an association is to be punished with an interdict.
In the previous Code (can 2335), Masonry is explicitly mentioned. As the declaration of 26 November 1983 explains, the omission of the name "Mason" in the present Church law is due to an "editorial criterion". Masonic associations are thus included under a more general heading which could include any other association conspiring against the Church (e.g. a specific communist party).
Clarification Concerning Catholics Becoming Freemasons
This taken into account along with the statements from our current Pope when he was Cardinal Ratzinger (which Theoden also posted)leads me to believe not much has changed regarding excommunication on Freemasonry. What do you think?