Hi. We created an LLC in 2013 (3 siblings of 4) for the purpose of obtaining a loan. We selling now, and want to add 4th sibling. How?

If it is real estate, all LLC members are disclosed on the transfer tax form, and will be liable for the gains.  You can give the cash any way you want.  Your accountant is telling you that if the fourth person is not listed as a member at closing, you will be paying their tax.

Income from capital gains is generally taxed at a lower rate than regular income.  Let's say that you invest in a business and also work for it.  Your salary from the business is regular income, and is taxed accordingly.  Your gain on any sale of your interest in the business, however, is a gain on your investment, i.e. capital gains, and taxed at a lower rate.  I don't know all the facts, but it seems that what your accountant is saying is that the 3 siblings who are now members of the llc will be gaining income from their investment in the llc - capital gains - but the non-member sibling will be getting (and being taxed on) regular income. I'm not sure that adding your 4th sibling as a member of the llc at this point, which you can easily accomplish by simpling selling him/her part of your interests, will really help with the tax issue.  It seems to me, a non-accountant, and again without all the facts, that the llc now has value, therefore, unless the 4th sibling pays fair value for his/her interest, his/her acquisition of an interest in the llc would be regular income to him/her, and taxed accordingly.  I think that your accountant is suggesting that you somehow reflect that your sibling has actually been a member of the llc since its inception.  If that's not actually true, you may be committing tax fraud by trying to "backdate" the 4th sibling's acquisition of an interest in the llc.