Absolutely, provided it is a valid baptism. A valid baptism is one that is:
- Done in the Trinitarian formula
- In the Nicene dogma of the Holy Trinity
Then your baptism is likely valid; under what church's or denomination's auspice's were you baptized?
The next step is to talk with the rector (priest-in-charge of the parish; if you are attending a mission, you'll speak to a vicar) or another clergy associated with that particular church. Announce your intention and ask if there are any confirmation classes that may be ongoing or be in the future, or if you can meet with someone to become educated in Episcopal theology. You will need to provide
proof of your baptism, which means you need to find out where you were baptized; they should have a copy of the record of your baptism there. You might have a copy or even the original yourself or your parents may. Either way, once you know where it is, tell the rector and she or he will send a letter of request to the place that has the record to obtain it. Otherwise, if you have it yourself, surrender it to the rector.
Once the church has the record of your baptism, you can become a specific member of the parish. The next step is confirmation, which will occur the next time the bishop of the diocese makes his or her visitation. At that time, you will then be formally entered into The Episcopal Church and the Anglican Communion at large.