For a 32% federal tax bracket investor, holding the business development company (BDC) Main Street Capital (MAIN) in a taxable account could result in $32,000 in federal tax on $100,000 of distributions. In contrast, Schwab U.S. Dividend Equity ETF (SCHD), which pays mostly qualified dividends, would incur about $15,000 in tax on the same distribution amount. Placing ordinary-income payers like MAIN into a Roth IRA can make these distributions permanently tax-free. The analysis suggests prioritizing Roth IRA space for high-ordinary-income payers like BDCs and REITs, while qualified-dividend payers like SCHD can be held in taxable accounts due to their already efficient tax treatment.