Can I adopt through LDS if I am not an active member?

Because LDS Family Services was created by the church to secure temple blessings for adopted children, you must be an active temple-recommend holding member, prepared to seal your children to you, in order to use their services.

And it can't be a recent thing necessarily. You also need to have been sealed to your spouse for at least 2 years prior to being approved to adopt (you may start the process).