As of this writing, the IRS tax code permits investors to use SD-IRA (self-directed IRA) and 401K for alternative investments, such as real estate syndications. However, in terms of tax there is a distinction between the SD-IRA and the 401K, with the SD-IR­­A having a UBIT tax while the 401K has no UBIT tax. Most Sponsors will accept investments through a SD-IRA, however, be sure that you’re working with a custodian with experience investing SD-IRAs in syndications to ensure you are following the IRS tax code.