I’m asked this question enough to have to think through how to answer. And usually, I’ll have to do some questioning myself to find out what the questioner means (or thinks he means). This is because “Reformed” is used in various, and quite imprecise, ways.
First, the broadest use seems to be a kind of identifier as non-charismatic. In some circles in South Africa, the two categories are not cessationist and continuationist, but charismatic and Reformed. This becomes the way a person tries to categorise your worship, understanding of spiritual gifts, and general tolerance for chaos in a morning service. In this sense, I suppose I’d accept the moniker.
Second, the slightly more accurate use identifies Reformed with Calvinistic. Here, the questioner wants to know where you stand on the doctrines of election, effectual call, perseverance of the saints, extent of the atonement, and such. If you line up with the five points of TULIP, the questioner considers you Reformed. Our church’s statement of faith would identify us with a broadly Calvinistic understanding of the doctrine of salvation, but by no means enough to satisfy the die-hards. If John MacArthur describes himself as a “leaky dispensationalist”, I’d be considered a leaky Calvinist by many, since I do not hold to particular redemption, I place faith before regeneration, and I understand the effectual call and unconditional election in ways that would not pass muster by the truly Reformed. However, if you’re happy to call a four-point Calvinist with Molinist views on foreknowledge Reformed, then so be it.
Third, the theologically accurate use of Reformed identifies a school of Protestant theology that involves a lot more than the five points of TULIP. Reformed theology necessarily includes covenant theology, and the form of covenant theology that requires paedobaptism. Reformed theology sees the sacraments as efficacious in some sense. The church is understood not as an opt-in, voluntary organisation, but as an opt-out, involuntary covenant community which one enters by being born into believing households that baptise in infancy. This strict form of covenant theology excludes premillennialism, and excludes believers baptism. In this very precise use of the term, Baptists cannot be Reformed: the term Reformed Baptist is an oxymoron. And if you think I’m making this up, get it from the horse’s mouth: Richard Muller of Calvin Seminary tells you what he thinks of Reformed Baptists: http://kimriddlebarger.squarespace.com/how-many-points/
In this sense, I am quite definitely not Reformed.
Two out of three? Or third strike you’re out?