Look up the annual pay South Carolina’s part-time House and Senate members receive, and you’ll likely find this misleading amount: $10,400.

All House and Senate members are paid more than double that amount and many receive closer to four times that much, with most of the income coming in the form of $1,000-a-month payments for “in-district expenses” that are, in fact, treated as taxable income and are counted toward lawmakers’ pensions.

So, they really receive $22,400 as a baseline, with the House speaker and Senate president receiving an extra $11,000. Then lawmakers are paid another $140 each day the Legislature is in session, which is worth roughly $8,000 to $10,000 more per year. The session is roughly five months, running from early January to the first Thursday in June

The $140-per-day payments are called per-diems or subsistence payments, rather than compensation. That money is described as a subsistence payment to cover meals and lodging, but lawmakers receive it regardless of where they live, regardless of actual expenses. If the daily payments were considered compensation, however, that could run afoul of the state constitution, which says “members of the General Assembly shall not receive any compensation for more than forty days of any one session.”

The salary, in-district expenses and per-diem money add up to about $30,000. Then lawmakers get an extra $600 if they head any of the more than two dozen committees, $600 for postage and mileage money for one round-trip to Columbia each week of the session —roughly $120 per trip for a Charleston-area lawmaker. Some also receive thousands of dollars from counties that don’t provide office space and staff for the delegation.

Add it all up and the typical House or Senate member takes home roughly $30,000 to $35,000 from the state — about triple the official salary — on top of whatever they earn in their day jobs. Charleston-area Sen. Larry Grooms, for example, reported state income of $35,032 for 2015.

Finally, lawmakers elected before 2012 enjoy generous pensions, far more valuable than other state employees receive. Lawmakers eligible to collect those pensions can claim them instead of their smaller $10,400 salaries, while still collecting the $12,000 for in-district expenses and the per diem payments.

For example, Sen. Hugh Leatherman of Florence in March reported income of $67,346 related to his legislative duties, with $36,149 from the retirement system accounting for more than half. The pension rules were changed for those elected in 2012 or later in response to the state’s pension fund shortfall, giving recently-elected lawmakers benefits similar to other retirement system participants.

This story was jointly reported and written by The Post and Courier and The Center for Public Integrity, a nonprofit, nonpartisan, investigative news group based in Washington, D.C.