In a limited partnership, someone has to be the general partner, and the general partner carries unlimited liability for the fund's obligations. No sponsor should occupy that seat personally, which is why the GP-as-LLC structure is close to universal in syndication.
Why most GPs default to an LLC filing Form 1065
An LLC gives the sponsor group a liability shield without adding a tax layer. A multi-member GP LLC is taxed as a partnership by default: it files Form 1065, pays no entity-level federal tax, and passes its share of fund economics (invested capital returns and the promote) to the principals on Schedule K-1, preserving the character of the underlying income. Capital gains stay capital gains all the way to your 1040, which is exactly what carried interest planning requires; the 3-year rule of Section 1061 applies at the interest level regardless of the LLC wrapper. A single-member GP LLC is disregarded for tax and its results land directly on the member's return, with the liability shield intact either way.
A C corporation GP would trap gains behind a second layer of tax; taxing the whole GP as an S corporation is usually wrong too, because S corp distribution rules and single-class-of-stock requirements fit badly with waterfall economics, and running promote through an S corp can compromise its character.
Liability isolation between deals
Serial sponsors take the shield one step further: a fresh GP LLC per deal or per fund. If a lender pursues a bad-boy carveout on Deal Three, a per-deal GP keeps Deals One and Two, and the management company, out of the blast radius. Formation costs and state fees are the price (some states, notably California, charge annual franchise fees per LLC and tax LLCs doing business there wherever formed), so small sponsors sometimes accept one GP entity across early deals and split later. Either way, the shield only holds if you respect it: separate bank accounts, signed documents in the entity's name, no commingling with personal funds, and state registrations kept current in the states where the properties sit.
Layering a management company above the GP
The mature sponsor structure is two entities with different jobs. The GP LLC holds the equity positions: co-invest capital and the promote, pass-through taxed, gains preserved. A separate management LLC earns the service income: acquisition fees, asset management fees, payroll for staff. Because fee income is ordinary and self-employment taxed, that management entity is the one that often elects S corporation treatment, letting principals take a reasonable W-2 salary plus distributions and trim the 15.3% layer. Keeping fees and promote in different boxes also protects the promote's carried interest character and keeps the fund's books clean for investors. The one-sentence answer: yes, make the GP an LLC, and as the fee stream grows, give the fees their own entity instead of stretching one LLC to do both jobs.