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Solo-401k interaction with employer sponsored 401k. Limits of contribution from Schedule C income
Alright, team!   I found answers to part 1) and part 2) that I've quote below, but still need help with 3).  The facts in the article below seem to point to the ability for the LLC to contribute profit sharing of up to 25% of the wages it paid SE tax on.  What part of the SE tax is that?  I assume the spirit of the law is to only allow the 25% on the taxable portion of the income, but given that I would have crossed the SS portion of SE tax, I am not 100%.  (From http://www.sensefinancial.com/services/solo401k/solo-401k-contribution/) Sole Proprietorship Employee Deferral The owner of a sole proprietorship who is under the age of 50 may make   employee deferral contributions of as much as $17,500 to a Solo 401(k)   plan for 2013 (Those 50 and older can tack on a $5,500 annual catch-up   contribution, bringing their annual deferral contribution to as much   as $23,000). Solo 401k contribution deadline rules dictate that plan   participant must formally elect to make an employee deferral   contribution by Dec. 31. However, the actual contribution can be made   up until the tax-filing deadline.  Pretax and/or after-tax (Roth)   funds can be used to make employee deferral contributions. Profit Sharing Contribution A sole proprietorship may make annual profit-sharing contributions to   a Solo 401(k) plan on behalf of the business owner and spouse.   Internal Revenue Code Section 401(a)(3) states that employer   contributions are limited to 25 percent of the business entity’s   income subject to self-employment tax. Schedule C sole-proprietors   must base their maximum contribution on earned income, an additional   calculation that lowers their maximum contribution to 20 percent of   earned income. IRS Publication 560 contains a step-by-step worksheet   for this calculation. In general, compensation can be defined as your   net earnings from self-employment activity.  This definition takes   into account the following eligible tax deductions: (1) the deduction   for half of self-employment tax and (2) the deduction for   contributions on your behalf to the Solo 401(k) plan.  A business   entity’s Solo 401(k) contributions for profit sharing component must   be made by its tax-filing deadline. Single Member LLC Employee Deferral The owner of a single member LLC who is under the age of 50 may make   employee deferral contributions of as much as $17,500 to a Solo 401(k)   plan for 2013 (Those 50 and older can tack on a $5,500 annual catch-up   contribution, bringing their annual deferral contribution to as much   as $23,000). Solo 401k contribution deadline rules dictate that plan   participant must formally elect to make an employee deferral   contribution by Dec. 31. However, the actual contribution can be made   up until the tax-filing deadline.  Pretax and/or after-tax (Roth)   funds can be used to make employee deferral contributions. Profit Sharing Contribution A single member LLC business may make annual profit-sharing   contributions to a Solo 401(k) plan on behalf of the business owner   and spouse. Internal Revenue Code Section 401(a)(3) states that   employer contributions are limited to 25 percent of the business   entity’s income subject to self-employment tax. Schedule C   sole-proprietors must base their maximum contribution on earned   income, an additional calculation that lowers their maximum   contribution to 20 percent of earned income. IRS Publication 560   contains a step-by-step worksheet for this calculation. In general,   compensation can be defined as your net earnings from self-employment   activity. This definition takes into account the following eligible   tax deductions: (i) the deduction for half of self-employment tax and   (ii) the deduction for contributions on your behalf to the Solo   401(k).  A single member LLC’s Solo 401(k) contributions for profit   sharing component must be made by its tax-filing deadline.